Introduction¶
Styles are used to change the look of your data while displayed on screen.
They are also used to determine the formatting for numbers.
Styles can be applied to the following aspects:
- font to set font size, color, underlining, etc.
- fill to set a pattern or color gradient
- border to set borders on a cell
- cell alignment
- protection
The following are the default values
>>> from openpyxl.styles import PatternFill, Border, Side, Alignment, Protection, Font >>> font = Font(name='Calibri', ... size=11, ... bold=False, ... italic=False, ... vertAlign=None, ... underline='none', ... strike=False, ... color='FF000000') >>> fill = PatternFill(fill_type=None, ... start_color='FFFFFFFF', ... end_color='FF000000') >>> border = Border(left=Side(border_style=None, ... color='FF000000'), ... right=Side(border_style=None, ... color='FF000000'), ... top=Side(border_style=None, ... color='FF000000'), ... bottom=Side(border_style=None, ... color='FF000000'), ... diagonal=Side(border_style=None, ... color='FF000000'), ... diagonal_direction=0, ... outline=Side(border_style=None, ... color='FF000000'), ... vertical=Side(border_style=None, ... color='FF000000'), ... horizontal=Side(border_style=None, ... color='FF000000') ... ) >>> alignment=Alignment(horizontal='general', ... vertical='bottom', ... text_rotation=0, ... wrap_text=False, ... shrink_to_fit=False, ... indent=0) >>> number_format = 'General' >>> protection = Protection(locked=True, ... hidden=False) >>>
Cell Styles and Named Styles¶
There are two types of styles: cell styles and named styles, also known as style templates.
Cell Styles¶
Cell styles are shared between objects and once they have been assigned they
cannot be changed. This stops unwanted side-effects such as changing the
style for lots of cells when only one changes.
>>> from openpyxl.styles import colors >>> from openpyxl.styles import Font, Color >>> from openpyxl import Workbook >>> wb = Workbook() >>> ws = wb.active >>> >>> a1 = ws['A1'] >>> d4 = ws['D4'] >>> ft = Font(color="FF0000") >>> a1.font = ft >>> d4.font = ft >>> >>> a1.font.italic = True # is not allowed # doctest: +SKIP >>> >>> # If you want to change the color of a Font, you need to reassign it:: >>> >>> a1.font = Font(color="FF0000", italic=True) # the change only affects A1
Copying styles¶
Styles can also be copied
>>> from openpyxl.styles import Font >>> from copy import copy >>> >>> ft1 = Font(name='Arial', size=14) >>> ft2 = copy(ft1) >>> ft2.name = "Tahoma" >>> ft1.name 'Arial' >>> ft2.name 'Tahoma' >>> ft2.size # copied from the 14.0
Colours¶
Colours for fonts, backgrounds, borders, etc. can be set in three ways: indexed, aRGB or theme. Indexed colours are the legacy implementation and the colours themselves depend upon the index provided with the workbook or with the application default. Theme colours are useful for complementary shades of colours but also depend upon the theme being present in the workbook. It is, therefore, advisable to use aRGB colours.
aRGB colours¶
RGB colours are set using hexadecimal values for red, green and blue.
>>> from openpyxl.styles import Font >>> font = Font(color="FF0000")
The alpha value refers in theory to the transparency of the colour but this is not relevant for cell styles. The default of 00 will prepended to any simple RGB value:
>>> from openpyxl.styles import Font >>> font = Font(color="00FF00") >>> font.color.rgb '0000FF00'
There is also support for legacy indexed colours as well as themes and tints.
>>> from openpyxl.styles.colors import Color >>> c = Color(indexed=32) >>> c = Color(theme=6, tint=0.5)
Indexed Colours¶
Index | |||||
---|---|---|---|---|---|
0-4 | 00000000 | 00FFFFFF | 00FF0000 | 0000FF00 | 000000FF |
5-9 | 00FFFF00 | 00FF00FF | 0000FFFF | 00000000 | 00FFFFFF |
10-14 | 00FF0000 | 0000FF00 | 000000FF | 00FFFF00 | 00FF00FF |
15-19 | 0000FFFF | 00800000 | 00008000 | 00000080 | 00808000 |
20-24 | 00800080 | 00008080 | 00C0C0C0 | 00808080 | 009999FF |
25-29 | 00993366 | 00FFFFCC | 00CCFFFF | 00660066 | 00FF8080 |
30-34 | 000066CC | 00CCCCFF | 00000080 | 00FF00FF | 00FFFF00 |
35-39 | 0000FFFF | 00800080 | 00800000 | 00008080 | 000000FF |
40-44 | 0000CCFF | 00CCFFFF | 00CCFFCC | 00FFFF99 | 0099CCFF |
45-49 | 00FF99CC | 00CC99FF | 00FFCC99 | 003366FF | 0033CCCC |
50-54 | 0099CC00 | 00FFCC00 | 00FF9900 | 00FF6600 | 00666699 |
55-60 | 00969696 | 00003366 | 00339966 | 00003300 | 00333300 |
60-63 | 00993300 | 00993366 | 00333399 | 00333333 | |
The indices 64 and 65 cannot be set and are reserved for the system foreground and background colours respectively.
Applying Styles¶
Styles are applied directly to cells
>>> from openpyxl.workbook import Workbook >>> from openpyxl.styles import Font, Fill >>> wb = Workbook() >>> ws = wb.active >>> c = ws['A1'] >>> c.font = Font(size=12)
Styles can also applied to columns and rows but note that this applies only
to cells created (in Excel) after the file is closed. If you want to apply
styles to entire rows and columns then you must apply the style to each cell
yourself. This is a restriction of the file format:
>>> col = ws.column_dimensions['A'] >>> col.font = Font(bold=True) >>> row = ws.row_dimensions[1] >>> row.font = Font(underline="single")
Styling Merged Cells¶
The merged cell behaves similarly to other cell objects.
Its value and format is defined in its top-left cell.
In order to change the border of the whole merged cell,
change the border of its top-left cell.
The formatting is generated for the purpose of writing.
>>> from openpyxl.styles import Border, Side, PatternFill, Font, GradientFill, Alignment >>> from openpyxl import Workbook >>> >>> wb = Workbook() >>> ws = wb.active >>> ws.merge_cells('B2:F4') >>> >>> top_left_cell = ws['B2'] >>> top_left_cell.value = "My Cell" >>> >>> thin = Side(border_style="thin", color="000000") >>> double = Side(border_style="double", color="ff0000") >>> >>> top_left_cell.border = Border(top=double, left=thin, right=thin, bottom=double) >>> top_left_cell.fill = PatternFill("solid", fgColor="DDDDDD") >>> top_left_cell.fill = fill = GradientFill(stop=("000000", "FFFFFF")) >>> top_left_cell.font = Font(b=True, color="FF0000") >>> top_left_cell.alignment = Alignment(horizontal="center", vertical="center") >>> >>> wb.save("styled.xlsx")
Using number formats¶
You can specify the number format for cells, or for some instances (ie datetime) it will automatically format.
>>> import datetime >>> from openpyxl import Workbook >>> wb = Workbook() >>> ws = wb.active >>> # set date using a Python datetime >>> ws['A1'] = datetime.datetime(2010, 7, 21) >>> >>> ws['A1'].number_format 'yyyy-mm-dd h:mm:ss' >>> >>> ws["A2"] = 0.123456 >>> ws["A2"].number_format = "0.00" # Display to 2dp
Edit Page Setup¶
>>> from openpyxl.workbook import Workbook >>> >>> wb = Workbook() >>> ws = wb.active >>> >>> ws.page_setup.orientation = ws.ORIENTATION_LANDSCAPE >>> ws.page_setup.paperSize = ws.PAPERSIZE_TABLOID >>> ws.page_setup.fitToHeight = 0 >>> ws.page_setup.fitToWidth = 1
Named Styles¶
In contrast to Cell Styles, Named Styles are mutable. They make sense when
you want to apply formatting to lots of different cells at once. NB. once you
have assigned a named style to a cell, additional changes to the style will
not affect the cell.
Once a named style has been registered with a workbook, it can be referred to simply by name.
Creating a Named Style¶
>>> from openpyxl.styles import NamedStyle, Font, Border, Side >>> highlight = NamedStyle(name="highlight") >>> highlight.font = Font(bold=True, size=20) >>> bd = Side(style='thick', color="000000") >>> highlight.border = Border(left=bd, top=bd, right=bd, bottom=bd)
Once a named style has been created, it can be registered with the workbook:
>>> wb.add_named_style(highlight)
But named styles will also be registered automatically the first time they are assigned to a cell:
>>> ws['A1'].style = highlight
Once registered, assign the style using just the name:
>>> ws['D5'].style = 'highlight'
Using builtin styles¶
The specification includes some builtin styles which can also be used.
Unfortunately, the names for these styles are stored in their localised
forms. openpyxl will only recognise the English names and only exactly as
written here. These are as follows:
- ‘Normal’ # same as no style
Number formats¶
- ‘Comma’
- ‘Comma [0]’
- ‘Currency’
- ‘Currency [0]’
- ‘Percent’
Informative¶
- ‘Calculation’
- ‘Total’
- ‘Note’
- ‘Warning Text’
- ‘Explanatory Text’
Text styles¶
- ‘Title’
- ‘Headline 1’
- ‘Headline 2’
- ‘Headline 3’
- ‘Headline 4’
- ‘Hyperlink’
- ‘Followed Hyperlink’
- ‘Linked Cell’
Comparisons¶
- ‘Input’
- ‘Output’
- ‘Check Cell’
- ‘Good’
- ‘Bad’
- ‘Neutral’
Highlights¶
- ‘Accent1’
- ‘20 % — Accent1’
- ‘40 % — Accent1’
- ‘60 % — Accent1’
- ‘Accent2’
- ‘20 % — Accent2’
- ‘40 % — Accent2’
- ‘60 % — Accent2’
- ‘Accent3’
- ‘20 % — Accent3’
- ‘40 % — Accent3’
- ‘60 % — Accent3’
- ‘Accent4’
- ‘20 % — Accent4’
- ‘40 % — Accent4’
- ‘60 % — Accent4’
- ‘Accent5’
- ‘20 % — Accent5’
- ‘40 % — Accent5’
- ‘60 % — Accent5’
- ‘Accent6’
- ‘20 % — Accent6’
- ‘40 % — Accent6’
- ‘60 % — Accent6’
- ‘Pandas’
For more information about the builtin styles please refer to the openpyxl.styles.builtins
Looks like the sheet is using the built-on colour index. The mapping for these is in the source of openpyxl.styles.color
COLOR_INDEX = (
'00000000', '00FFFFFF', '00FF0000', '0000FF00', '000000FF', #0-4
'00FFFF00', '00FF00FF', '0000FFFF', '00000000', '00FFFFFF', #5-9
'00FF0000', '0000FF00', '000000FF', '00FFFF00', '00FF00FF', #10-14
'0000FFFF', '00800000', '00008000', '00000080', '00808000', #15-19
'00800080', '00008080', '00C0C0C0', '00808080', '009999FF', #20-24
'00993366', '00FFFFCC', '00CCFFFF', '00660066', '00FF8080', #25-29
'000066CC', '00CCCCFF', '00000080', '00FF00FF', '00FFFF00', #30-34
'0000FFFF', '00800080', '00800000', '00008080', '000000FF', #35-39
'0000CCFF', '00CCFFFF', '00CCFFCC', '00FFFF99', '0099CCFF', #40-44
'00FF99CC', '00CC99FF', '00FFCC99', '003366FF', '0033CCCC', #45-49
'0099CC00', '00FFCC00', '00FF9900', '00FF6600', '00666699', #50-54
'00969696', '00003366', '00339966', '00003300', '00333300', #55-59
'00993300', '00993366', '00333399', '00333333', 'System Foreground', 'System Background' #60-64
)
11L corresponds to 0000FF00 (hexadecimal) for which the rgb tuple would be green (0,255,0).
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To add color to Excel cells we will be using the Openpyxl Python Library. The Openpyxl module allows us to read and modify Excel files using Python.
Approach 1:
Using the Openpyxl module, even small tasks can be done very efficiently and easily in excel.
Input File:
Only declare the excel name with .xlsx form if the file exists in the same folder as where the code exists. If the file exists in another folder then the linking has to be done by giving the entire path source.
Installing the OpenPyxl module: In order to install the openpyxl module via pip run the below command in the terminal of the user’s choice:
pip install openpyxl
Example:
Python3
import
openpyxl
from
openpyxl.styles
import
PatternFill
wb
=
openpyxl.load_workbook(
"GFGCoursePrices.xlsx"
)
ws
=
wb[
'Sheet1'
]
To fill the color in the cell you have to declare the pattern type and fgColor. Now create a working sheet variable and initialize it with the current sheet you are working on using the syntax
Python3
colors
=
[
'00660066'
,
'00FFFFCC'
,
'00FF0000'
,
'0000FF00'
,
'00660066'
]
fillers
=
[]
for
color
in
colors:
temp
=
PatternFill(patternType
=
'solid'
,
fgColor
=
color)
fillers.append(temp)
Here we need to keep in mind that colors value has to be strictly hex values not like ‘Blue’ ,’yellow’ , ‘red’ etc. It will not work. Otherwise, we will encounter an error like below:
Finally, you have to save changes using the .save() function. To fill each cell, you have to use the .fill() function depicted by the following syntax.
Python3
cell_ids
=
[
'B2'
,
'B3'
,
'B4'
,
'B5'
,
'A2'
]
for
i
in
range
(
5
):
ws[cell_ids[i]].fill
=
fillers[i]
wb.save(
"GFGCoursePrices.xlsx"
)
Output:
Approach 2:
We can also take the help of Color method of the openpyxl.styles.colors. Here we can pass integer values (0-63) and while coloring them we need to pass them as the value of a keyworded argument indexed.
Python3
import
openpyxl
from
openpyxl.styles
import
PatternFill
from
openpyxl.styles.colors
import
Color
wb
=
openpyxl.load_workbook(
"geeks.xlsx"
)
ws
=
wb[
'Sheet1'
]
colors
=
[
6
,
3
,
48
,
37
,
28
]
fillers
=
[]
for
color
in
colors:
temp
=
PatternFill(patternType
=
'solid'
,
fgColor
=
Color(indexed
=
color))
fillers.append(temp)
cell_ids
=
[
'B2'
,
'B3'
,
'B4'
,
'B5'
,
'A2'
]
for
i
in
range
(
5
):
ws[cell_ids[i]].fill
=
fillers[i]
wb.save(
"geeks.xlsx"
)
Output:
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OpenPyXL gives you the ability to style your cells in many different ways. Styling cells will give your spreadsheets pizazz! Your spreadsheets can have some pop and zing to them that will help differentiate them from others. However, don’t go overboard! If every cell had a different font and color, your spreadsheet would look like a mess.
You should use the skills that you learn in this article sparingly. You’ll still have beautiful spreadsheets that you can share with your colleagues. If you would like to learn more about what styles OpenPyXL supports, you should check out their documentation.
In this article, you will learn about the following:
- Working with fonts
- Setting the alignment
- Adding a border
- Changing the cell background-color
- Inserting images into cells
- Styling merged cells
- Using a built-in style
- Creating a custom named style
Now that you know what you’re going to learn, it’s time to get started by discovering how to work with fonts using OpenPyXL!
Working with Fonts
You use fonts to style your text on a computer. A font controls the size, weight, color, and style of the text you see on-screen or in print. There are thousands of fonts that your computer can use. Microsoft includes many fonts with its Office products.
When you want to set a font with OpenPyXL, you will need to import the Font
class from openpyxl.styles
. Here is how you would do the import:
from openpyxl.styles import Font
The Font
class takes many parameters. Here is the Font
class’s full list of parameters according to OpenPyXL’s documentation:
class openpyxl.styles.fonts.Font(name=None, sz=None, b=None, i=None, charset=None, u=None, strike=None, color=None, scheme=None, family=None, size=None, bold=None, italic=None, strikethrough=None, underline=None, vertAlign=None, outline=None, shadow=None, condense=None, extend=None)
The following list shows the parameters you are most likely to use and their defaults:
- name=’Calibri’
- size=11
- bold=False
- italic=False
- vertAlign=None
- underline=’none’
- strike=False
- color=’FF000000′
These settings allow you to set most of the things you’ll need to make your text look nice. Note that the color names in OpenPyXL use hexadecimal values to represent RGB (red, green, blue) color values. You can set whether or not the text should be bold, italic, underlined, or struck-through.
To see how you can use fonts in OpenPyXL, create a new file named font_sizes.py
and add the following code to it:
# font_sizes.py import openpyxl from openpyxl.styles import Font def font_demo(path): workbook = openpyxl.Workbook() sheet = workbook.active cell = sheet["A1"] cell.font = Font(size=12) cell.value = "Hello" cell2 = sheet["A2"] cell2.font = Font(name="Arial", size=14, color="00FF0000") sheet["A2"] = "from" cell2 = sheet["A3"] cell2.font = Font(name="Tahoma", size=16, color="00339966") sheet["A3"] = "OpenPyXL" workbook.save(path) if __name__ == "__main__": font_demo("font_demo.xlsx")
This code uses three different fonts in three different cells. In A1, you use the default, which is Calibri. Then in A2, you set the font size to Arial and increase the size to 14 points. Finally, in A3, you change the font to Tahoma and the font size to 16 points.
For the second and third fonts, you also change the text color. In A2, you set the color to red, and in A3, you set the color to green.
When you run this code, your output will look like this:
Try changing the code to use other fonts or colors. If you want to get adventurous, you should try to make your text bold or italicized.
Now you’re ready to learn about text alignment.
Setting the Alignment
You can set alignment in OpenPyXL by using openpyxl.styles.Alignment
. You use this class to rotate the text, set text wrapping, and for indentation.
Here are the defaults that the Alignment
class uses:
- horizontal=’general’
- vertical=’bottom’
- text_rotation=0
- wrap_text=False
- shrink_to_fit=False
- indent=0
It’s time for you to get some practice in. Open up your Python editor and create a new file named alignment.py
. Then add this code to it:
# alignment.py from openpyxl import Workbook from openpyxl.styles import Alignment def center_text(path, horizontal="center", vertical="center"): workbook = Workbook() sheet = workbook.active sheet["A1"] = "Hello" sheet["A1"].alignment = Alignment(horizontal=horizontal, vertical=vertical) sheet["A2"] = "from" sheet["A3"] = "OpenPyXL" sheet["A3"].alignment = Alignment(text_rotation=90) workbook.save(path) if __name__ == "__main__": center_text("alignment.xlsx")
You will center the string both horizontally and vertically in A1 when you run this code. Then you use the defaults for A2. Finally, for A3, you rotate the text 90 degrees.
Try running this code, and you will see something like the following:
That looks nice! It would be best if you took the time to try out different text_rotation
values. Then try changing the horizontal
and vertical
parameters with different values. Pretty soon, you will be able to align your text like a pro!
Now you’re ready to learn about adding borders to your cells!
Adding a Border
OpenPyXL gives you the ability to style the borders on your cell. You can specify a different border style for each of the four sides of a cell.
You can use any of the following border styles:
- ‘dashDot’
- ‘dashDotDot’
- ‘dashed’
- ‘dotted’
- ‘double’
- ‘hair’
- ‘medium’
- ‘mediumDashDot’
- ‘mediumDashDotDot’,
- ‘mediumDashed’
- ‘slantDashDot’
- ‘thick’
- ‘thin’
Open your Python editor and create a new file named border.py
. Then enter the following code in your file:
# border.py from openpyxl import Workbook from openpyxl.styles import Border, Side def border(path): pink = "00FF00FF" green = "00008000" thin = Side(border_style="thin", color=pink) double = Side(border_style="double", color=green) workbook = Workbook() sheet = workbook.active sheet["A1"] = "Hello" sheet["A1"].border = Border(top=double, left=thin, right=thin, bottom=double) sheet["A2"] = "from" sheet["A3"] = "OpenPyXL" sheet["A3"].border = Border(top=thin, left=double, right=double, bottom=thin) workbook.save(path) if __name__ == "__main__": border("border.xlsx")
This code will add a border to cell A1 and A3. The top and bottom of A1 use a “double” border style and are green, while the cell sides are using a “thin” border style and are colored pink.
Cell A3 uses the same borders but swaps them so that the sides are now green and the top and bottom are pink.
You get this effect by creating Side
objects in the border_style
and the color
to be used. Then you pass those Side
objects to a Border
class, which allows you to set each of the four sides of a cell individually. To apply the Border
to a cell, you must set the cell’s border
attribute.
When you run this code, you will see the following result:
This image is zoomed in a lot so that you can easily see the borders of the cells. It would be best if you tried modifying this code with some of the other border styles mentioned at the beginning of this section so that you can see what else you can do.
Changing the Cell Background Color
You can highlight a cell or a range of cells by changing its background color. Highlighting a cell is more eye-catching than changing the text’s font or color in most cases. OpenPyXL gives you a class called PatternFill
that you can use to change a cell’s background color.
The PatternFill
class takes in the following arguments (defaults included below):
- patternType=None
- fgColor=Color()
- bgColor=Color()
- fill_type=None
- start_color=None
- end_color=None
There are several different fill types you can use. Here is a list of currently supported fill types:
- ‘none’
- ‘solid’
- ‘darkDown’
- ‘darkGray’
- ‘darkGrid’
- ‘darkHorizontal’
- ‘darkTrellis’
- ‘darkUp’
- ‘darkVertical’
- ‘gray0625’
- ‘gray125’
- ‘lightDown’
- ‘lightGray’
- ‘lightGrid’
- ‘lightHorizontal’
- ‘lightTrellis’
- ‘lightUp’
- ‘lightVertical’
- ‘mediumGray’
Now you have enough information to try setting the background color of a cell using OpenPyXL. Open up a new file in your Python editor and name it background_colors.py
. Then add this code to your new file:
# background_colors.py from openpyxl import Workbook from openpyxl.styles import PatternFill def background_colors(path): workbook = Workbook() sheet = workbook.active yellow = "00FFFF00" for rows in sheet.iter_rows(min_row=1, max_row=10, min_col=1, max_col=12): for cell in rows: if cell.row % 2: cell.fill = PatternFill(start_color=yellow, end_color=yellow, fill_type = "solid") workbook.save(path) if __name__ == "__main__": background_colors("bg.xlsx")
This example will iterate over nine rows and 12 columns. It will set every cell’s background color to yellow if that cell is in an odd-numbered row. The cells with their background color changes will be from column A through column L.
When you want to set the cell’s background color, you set the cell’s fill
attribute to an instance of PatternFill
. In this example, you specify a start_color
and an end_color
. You also set the fill_type
to “solid”. OpenPyXL also supports using a GradientFill
for the background.
Try running this code. After it runs, you will have a new Excel document that looks like this:
Here are some ideas that you can try out with this code:
- Change the number of rows or columns that are affected
- Change the color that you are changing to
- Update the code to color the even rows with a different color
- Try out other fill types
Once you are done experimenting with background colors, you can learn about inserting images in your cells!
Inserting Images into Cells
OpenPyXL makes inserting an image into your Excel spreadsheets nice and straightforward. To make this magic happen, you use the Worksheet
object’s add_image()
method. This method takes in two arguments:
img
– The path to the image file that you are insertinganchor
– Provide a cell as a top-left anchor of the image (optional)
For this example, you will be using the Mouse vs. Python logo:
The GitHub repository for this book has the image for you to use.
Once you have the image downloaded, create a new Python file and name it insert_image.py
. Then add the following:
# insert_image.py from openpyxl import Workbook from openpyxl.drawing.image import Image def insert_image(path, image_path): workbook = Workbook() sheet = workbook.active img = Image("logo.png") sheet.add_image(img, "B1") workbook.save(path) if __name__ == "__main__": insert_image("logo.xlsx", "logo.png")
Here you pass in the path to the image that you wish to insert. To insert the image, you call add_image()
. In this example, you are hard-coding to use cell B1 as the anchor cell. Then you save your Excel spreadsheet.
If you open up your spreadsheet, you will see that it looks like this:
You probably won’t need to insert an image into an Excel spreadsheet all that often, but it’s an excellent skill to have.
Styling Merged Cells
Merged cells are cells where you have two or more adjacent cells merged into one. If you want to set the value of a merged cell with OpenPyXL, you must use the top left-most cell of the merged cells.
You also must use this particular cell to set the style for the merged cell as a whole. You can use all the styles and font settings you used on an individual cell with the merged cell. However, you must apply the style to the top-left cell for it to apply to the entire merged cell.
You will understand how this works if you see some code. Go ahead and create a new file named style_merged_cell.py
. Now enter this code in your file:
# style_merged_cell.py from openpyxl import Workbook from openpyxl.styles import Font, Border, Side, GradientFill, Alignment def merge_style(path): workbook = Workbook() sheet = workbook.active sheet.merge_cells("A2:G4") top_left_cell = sheet["A2"] light_purple = "00CC99FF" green = "00008000" thin = Side(border_style="thin", color=light_purple) double = Side(border_style="double", color=green) top_left_cell.value = "Hello from PyOpenXL" top_left_cell.border = Border(top=double, left=thin, right=thin, bottom=double) top_left_cell.fill = GradientFill(stop=("000000", "FFFFFF")) top_left_cell.font = Font(b=True, color="FF0000", size=16) top_left_cell.alignment = Alignment(horizontal="center", vertical="center") workbook.save(path) if __name__ == "__main__": merge_style("merged_style.xlsx")
Here you create a merged cell that starts at A2 (the top-left cell) through G4. Then you set the cell’s value, border, fill, font and alignment.
When you run this code, your new spreadsheet will look like this:
Doesn’t that look nice? You should take some time and try out some different styles on your merged cell. Maybe come up with a better gradient than the gray one used here, for example.
Now you’re ready to learn about OpenPyXL’s built-in styles!
Using a Built-in Style
OpenPyXL comes with multiple built-in styles that you can use as well. Rather than reproducing the entire list of built-in styles in this book, you should go to the official documentation as it will be the most up-to-date source for the style names.
However, it is worth noting some of the styles. For example, here are the number format styles you can use:
- ‘Comma’
- ‘Comma [0]’
- ‘Currency’
- ‘Currency [0]’
- ‘Percent’
You can also apply text styles. Here is a listing of those styles:
- ‘Title’
- ‘Headline 1’
- ‘Headline 2’
- ‘Headline 3’
- ‘Headline 4’
- ‘Hyperlink’
- ‘Followed Hyperlink’
- ‘Linked Cell’
OpenPyXL has several other built-in style groups. You should check out the documentation to learn about all the different styles that are supported.
Now that you know about some of the built-in styles you can use, it’s time to write some code! Create a new file and name it builtin_styls.py
. Then enter the following code:
# builtin_styles.py from openpyxl import Workbook def builtin_styles(path): workbook = Workbook() sheet = workbook.active sheet["A1"].value = "Hello" sheet["A1"].style = "Title" sheet["A2"].value = "from" sheet["A2"].style = "Headline 1" sheet["A3"].value = "OpenPyXL" sheet["A3"].style = "Headline 2" workbook.save(path) if __name__ == "__main__": builtin_styles("builtin_styles.xlsx")
Here you apply three different styles to three different cells. You use “Title”, “Headline 1” and “Headline 2”, specifically.
When you run this code, you will end up having a spreadsheet that looks like this:
As always, you should try out some of the other built-in styles. Trying them out is the only way to determine what they do and if they will work for you.
But wait! What if you wanted to create your style? That’s what you will cover in the next section!
Creating a Custom Named Style
You can create custom styles of your design using OpenPyXL as well. To create your style, you must use the NamedStyle
class.
The NamedStyle
class takes the following arguments (defaults are included too):
- name=”Normal”
- font=Font()
- fill=PatternFill()
- border=Border()
- alignment=Alignment()
- number_format=None
- protection=Protection()
- builtinId=None
- hidden=False
- xfId=None
You should always provide your own name
to your NamedStyle
to keep it unique. Go ahead and create a new file and call it named_style.py
. Then add this code to it:
# named_style.py from openpyxl import Workbook from openpyxl.styles import Font, Border, Side, NamedStyle def named_style(path): workbook = Workbook() sheet = workbook.active red = "00FF0000" font = Font(bold=True, size=22) thick = Side(style="thick", color=red) border = Border(left=thick, right=thick, top=thick, bottom=thick) named_style = NamedStyle(name="highlight", font=font, border=border) sheet["A1"].value = "Hello" sheet["A1"].style = named_style sheet["A2"].value = "from" sheet["A3"].value = "OpenPyXL" workbook.save(path) if __name__ == "__main__": named_style("named_style.xlsx")
Here you create a Font()
, Side()
, and Border()
instance to pass to your NamedStyle()
. Once you have your custom style created, you can apply it to a cell by setting the cell’s style
attribute. Applying a custom style is done in the same way as you applied built-in styles!
You applied the custom style to the cell, A1.
When you run this code, you will get a spreadsheet that looks like this:
Now it’s your turn! Edit the code to use a Side
style, which will change your border. Or create multiple Side
instances so you can make each side of the cell unique. Play around with different fonts or add a custom background color!
Wrapping Up
You can do a lot of different things with cells using OpenPyXL. The information in this article gives you the ability to format your data in beautiful ways.
In this article, you learned about the following topics:
- Working with fonts
- Setting the alignment
- Adding a border
- Changing the cell background-color
- Inserting images into cells
- Styling merged cells
- Using a built-in style
- Creating a custom named style
You can take the information that you learned in this article to make beautiful spreadsheets. You can highlight exciting data by changing the cell’s background color or font. You can also change the cell’s format by using a built-in style. Go ahead and give it a try.
Experiment with the code in this article and see how powerful and valuable OpenPyXL is when working with cells.
Related Reading
- Reading Spreadsheets with OpenPyXL and Python
- Creating Spreadsheets with OpenPyXL and Python
- Automating Excel with Python (book)
Привет всем! Обычно вопросы (пусть и не многочисленные, но от этого не менее интересные) мне приходят на почту или в Telegram. Сегодня вопрос был задан в Facebook: Как узнать цвет ячейки в Excel-файле с помощью Python? Ответ, как всегда после того, как разберешься — оказывается весьма простым:
-
import openpyxl #Подключаем библиотеку <a href="https://openpyxl.readthedocs.io" rel="noopener noreferrer" target="_blank">Openpyxl</a>
-
path = 'path to file'
-
workbook = openpyxl.load_workbook(path) #Собственно - читаем сам файл
-
sheets_list = workbook.sheetnames #Получаем список всех листов в книге
-
sheet_active = workbook[sheets_list[0]] #Делаем активным самый первый лист в книге
-
-
cell_fill = sheet_active['A1'].fill.start_color.index #Получаем цвет ячейки
-
cell_fill = '#' + cell_fill
-
print(cell_fill) #Выводим на экран :)
Собственно, это все 🙂 Спасибо за внимание! Как всегда — для вопросов открыта почта и есть Telegram 🙂
Больше …
Привет всем! Только что столкнулся с задачей работы со временем…
The openpyxl Python library provides various different modules to read and modify Excel files. Using this module, we can work on the Excel workbooks very easily and efficiently. In this section, we will discuss how we can add the background color to Excel cells in Python using the openpyxl library.
Program to add color to Excel cells in Python
Note: Before starting programming, create an Excel file with some data, or you can choose any of your existing Excel files.
Example:
Step1: Import the openpyxl Library and modules to the Python program for adding color to the cell.
import openpyxl from openpyxl.styles import PatternFill
Note: openpyxl.styles provides various different functions that style your cells in many different ways, like changing the color, font, alignment, border, etc.
Step2: Connect/Link your Excel workbook file and corresponding workbook’s working Sheet with the Python Program.
wb = openpyxl.load_workbook("//home//codespeedy//Documents//MyWorkBook.xlsx") #path to the Excel file ws = wb['Sheet1'] #Name of the working sheet
Step3: Call the PaternFill() function with the Pattern type and foreground color parameters of your choice.
fill_cell = PatternFill(patternType='solid', fgColor='C64747') #You can give the hex code for different color
Step4: Lastly, fill the cell with color by using the name of the particular cell of the working sheet, and save the changes to the workbook.
ws['B2'].fill = fill_cell # B2 is the name of the cell to be fill with color wb.save("//home//codespeedy//Documents//MyWorkBook.xlsx")
Here is the complete Python Program:
import openpyxl from openpyxl.styles import PatternFill wb = openpyxl.load_workbook("//home//codespeedy//Documents//MyWorkBook.xlsx") ws = wb['Sheet1'] #Name of the working sheet fill_cell1 = PatternFill(patternType='solid', fgColor='FC2C03') fill_cell2 = PatternFill(patternType='solid', fgColor='03FCF4') fill_cell3 = PatternFill(patternType='solid', fgColor='35FC03') fill_cell4 = PatternFill(patternType='solid', fgColor='FCBA03') ws['B2'].fill = fill_cell1 ws['B3'].fill = fill_cell2 ws['B4'].fill = fill_cell3 ws['B5'].fill = fill_cell4 wb.save("//home//sanamsahoo0876//Documents//MyWorkBook.xlsx")
Now, close the Excel application and reopen it to see the changes.
Output:
Hope this article has helped you understand adding color to the Excel cells using Python easily.
You can also read, Python Program to Merge Excel Cells using openpyxl
What will we cover in this tutorial?
We will learn how you can dynamically format the cells in Excel to have a specific color based on the value of a function – all done from Python.
As an example we will color the cells of two columns depending on which is larger.
In this concrete example we will collect historical stock prices and calculate the Moving Averages of 50 and 200 days on the closing price. In a crossover way to utilize moving averages, you would send a buy-signal when the 50-day moving average crosses above the 200-day moving average and a sell-signal if the other way around.
Step 1: Collect the data from Yahoo! Finance using Pandas-datareader
A great library to use to collect financial data is the Pandas-datareader.
We will collect data from Yahoo! Finance. As an example we will use General Motors historical stock data.
This can be done as follows.
import pandas_datareader as pdr import datetime as dt start = dt.datetime(2019, 1, 1) ticker = pdr.get_data_yahoo("GM", start)
This will result in a Pandas DataFrame with data similar to this.
High Low Open Close Volume Adj Close Date 2019-01-02 33.810001 32.410000 32.849998 33.639999 7662300.0 31.893360 2019-01-03 33.680000 32.200001 33.340000 32.250000 11618300.0 30.575533 2019-01-04 33.570000 32.430000 32.799999 33.330002 10784000.0 31.599455 2019-01-07 34.970001 33.480000 33.709999 34.360001 10722300.0 32.575977 2019-01-08 35.680000 34.490002 35.000000 34.810001 10532900.0 33.002617
Step 2: Calculate the Moving Averages
The moving average can be calculated by applying the rolling() and mean() methods on the DataFrame.
The rolling() creates a window size which is the number of observations used for calculating the statistic.
To calculate the Moving Average of window size 50 will use the last 50 data points to calculate the mean. To be consistent with Yahoo! Finance way of calculate the value, they use the Close price.
import pandas_datareader as pdr import datetime as dt import xlsxwriter import pandas as pd start = dt.datetime(2019, 1, 1) ticker = pdr.get_data_yahoo("GM", start) ticker['MA50'] = ticker['Close'].rolling(50).mean() ticker['MA200'] = ticker['Close'].rolling(200).mean()
Which will give a tail similar to this output.
High Low Open ... Adj Close MA50 MA200 Date ... 2020-12-14 42.540001 41.419998 42.490002 ... 41.619999 38.5632 29.03155 2020-12-15 42.160000 41.310001 41.990002 ... 41.660000 38.7772 29.08725 2020-12-16 41.869999 40.810001 41.790001 ... 41.419998 38.9976 29.13670 2020-12-17 42.029999 41.430000 41.709999 ... 42.029999 39.2058 29.19635 2020-12-18 42.042801 41.139999 42.020000 ... 41.389999 39.3894 29.25985
Where the Moving Averages are added to the DataFrame.
Step 3: Exporting to Excel using XlsxWriter
We will use the powerful XlsxWriter to create our Excel sheet.
You can write the DataFrame directly by using to_excel(…), but we want to do more than that. Hence, we use the XlsxWriter directly.
import pandas_datareader as pdr import datetime as dt import pandas as pd start = dt.datetime(2019, 1, 1) ticker = pdr.get_data_yahoo("GM", start) ticker['MA50'] = ticker['Close'].rolling(50).mean() ticker['MA200'] = ticker['Close'].rolling(200).mean() # We only want the index as a date and not datetime object ticker.index = ticker.index.date # We skip the first 200 entries, as it they do not have the MA200 ticker = ticker.iloc[200:] # We reverse the DataFrame to have newest first ticker = ticker.iloc[::-1] # Create a Pandas Excel writer using XlsxWriter as the engine. writer = pd.ExcelWriter('moving_average.xlsx', engine='xlsxwriter') # Convert the dataframe to an XlsxWriter Excel object. ticker.to_excel(writer, sheet_name='Moving Averages') # Remember to close the writer to write the Excel sheet writer.close()
This will create an Excel sheet similar to this one.
Step 4: Adding formatting to the cells
This is a bit more complex as we need to do the magic here.
We first need to create a reference to the sheet (worksheet) we work on to access the functionality.
The first thing we do is to resize column A, such that it opens in the correct size to see the date. This is done by using set_column(…).
Then we create a format, which can be applied on Excel cells. This is how we color them. Hence, we create one for green cells and later one for red cells.
We insert them by using conditional_format(…), which a range of cells. This can be applied in different ways, we use the A1 notation.
The options parameter in conditional_format(…) must be a dictionary containing the parameters that describe the type and style of the conditional format. To see details of the format please refer to the manual.
import pandas_datareader as pdr import datetime as dt import pandas as pd start = dt.datetime(2019, 1, 1) ticker = pdr.get_data_yahoo("GM", start) ticker['MA50'] = ticker['Close'].rolling(50).mean() ticker['MA200'] = ticker['Close'].rolling(200).mean() # We only want the index as a date and not datetime object ticker.index = ticker.index.date # We skip the first 200 entries, as it they do not have the MA200 ticker = ticker.iloc[200:] # We reverse the DataFrame to have newest first ticker = ticker.iloc[::-1] # Create a Pandas Excel writer using XlsxWriter as the engine. writer = pd.ExcelWriter('moving_average.xlsx', engine='xlsxwriter') # Convert the dataframe to an XlsxWriter Excel object. ticker.to_excel(writer, sheet_name='Moving Averages') # Get the xlsxwriter objects from the dataframe writer object. workbook = writer.book worksheet = writer.sheets['Moving Averages'] # Resize the column A worksheet.set_column("A:A", 12) # Calculate the last row number (we insert first DataFrame row in row 2) last_row = len(ticker) + 1 # Create a format for a green cell cell_format_green = workbook.add_format() cell_format_green.set_bg_color('green') # Create a conditional formatted of type formula worksheet.conditional_format('H2:I{}'.format(last_row), {'type': 'formula', 'criteria': '=$H2>=$I2', 'format': cell_format_green}) # Create a format for a red cell cell_format_red = workbook.add_format() cell_format_red.set_bg_color('red') # Create a conditional formatted of type formula worksheet.conditional_format('H2:I{}'.format(last_row), {'type': 'formula', 'criteria': '=$H2<$I2', 'format': cell_format_red}) # Remember to close the writer writer.close()
This will result in the expected Excel sheet.
Step 5: Validating it works as expected
Now for the final test.
The colors should be updated dynamically. Let’s try to change the value and see what happens.
It does. If we change the value of H2 to 10, it turns the cells to red.
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Last Updated on July 14, 2022 by
This tutorial will show you how to use the Python openpyxl library to customize Excel formatting such as cell color, alignment, borderlines, etc. We’ll continue with the previous example to make our monthly budget spreadsheet look prettier.
Library
The only library required is openpyxl, type the following in the command prompt window to install the library:
pip install openpyxl
In openpyxl, each Cell object has a bunch of attributes we can use for formatting:
Attribute | Usage |
Cell.font | font style, size, color, etc |
Cell.number_format | number formats |
Cell.fill | cell color and pattern |
Cell.border | cell border |
Cell.alignment | text alignment |
Collectively, these attributes are called styles but I still prefer calling them just formats. One thing to note is that we can apply styles to only one cell at a time. So we’ll need to do a loop in order to format a range of cells.
Color – Pattern (solid) Fill
There are two types of cell color formatting: Pattern Fill and Gradient Fill.
We use Pattern Fill to make a solid color or a pattern for the cell. A Pattern Fill refers to the following formatting in Excel:
The below code changes cells B11:C11 to a light gray background and changes cells B19:C19 to a dotted background known as 6.25% Gray (found in the Pattern Style dropbox). To make the formatting easier to see, we’ll hide all gridlines in Excel by setting ws.sheet_view.showGridLines to False.
from openpyxl.styles import PatternFill, GradientFill
ws.sheet_view.showGridLines = False
for c in ws['B11:C11'][0]:
c.fill = PatternFill('solid', fgColor = 'F2F2F2')
for c in ws['B19:C19'][0]:
c.fill = PatternFill('gray0625')
Color – Gradient Fill
A Gradient Fill usually takes two colors and interpolates colors between them and fills the cell background. The following code takes a cyan color (’85E4F7′) and a light blue color (‘4617F1’) for the gradient fill. You can change the two RGB hex code inside the stop argument to any color to create your own gradient fill.
ws['E7'].fill = GradientFill('linear', stop = ('85E4F7','4617F1'))
ws['E9'].fill = GradientFill('linear', stop = ('85E4F7','4617F1'))
ws['E11'].fill = GradientFill('linear', stop = ('85E4F7','4617F1'))
ws['E13'].fill = GradientFill('linear', stop = ('85E4F7','4617F1'))
Borderlines
Borderlines refer to the four sides of a cell. With openpyxl, we can control the style (solid vs dash, etc), thickness, color, and position of the borderlines. We need two objects to model a cell’s borderline: Border and Side.
A Border can contain one or multiple Sides. Then we assign the cell.border attribute to a Border object to create the borderlines.
from openpyxl.styles import Border, Side
double = Side(border_style="double", color="4617F1")
thin = Side(border_style="thin", color="4617F1")
regular = Side(border_style="medium", color="000000")
## For the title cells B2 to F2
for c in ws['B2:F2'][0]:
c.border = Border(bottom=double, top=thin)
no_left_side = Border(top = regular,bottom=regular,right=regular)
no_right_side = Border(top = regular,bottom=regular, left=regular)
box = Border(top = regular,bottom=regular, left=regular,right=regular)
## For the "table-like" cells
for c in ws['B8:B11']+ws['B15:B19']:
c[0].border = no_left_side
for c in ws['C8:C11']+ws['C15:C19']:
c[0].border = no_right_side
Text Alignment
We use the Alignment object to model text/number alignment within a cell, then assign the cell.alignment attribute to the object.
from openpyxl.styles import Alignment
center_align = Alignment(horizontal='center', vertical='center')
for c in ws['C8:C11']+ws['C15:C19']:
c[0].border = no_right_side
c[0].alignment = center_align
for c in ws['F7:F14']:
c[0].alignment = center_align
Additional Resources
Python & Excel – Number Format
Python openpyxl – How to Insert Rows, Columns in Excel
Adjust Excel Fonts using Python openpyxl
Write Data to Excel using Python