Conditional format cell in column based on it corresponding value in another column

Question

I have created an excel file from a dataframe that looks like this:

In [215]: import pandas as pd

In [216]: df = pd.DataFrame({"Name": ["A", "B", "C"], "Status": ['y', 'n', 'yy']})

In [217]: df
Out[217]:
  Name  Status
0    A       y
1    B       n
2    C      yy

How can I set the bg_color for "Name" based on the value of Status? I have tried a couple of options without success:

format1 = workbook.add_format({"bg_color": "#669731"})
format2 = workbook.add_format({"bg_color": "#FFFA22"})
format3 = workbook.add_format({"bg_color": "#A43829"})

Option 1

worksheet.conditional_format("A2",
                             {"type": "formula",
                              "criteria": "=ISNUMBER(SEARCH('y', B2))",
                              "format": format1
                             }
)

Option 2

worksheet.conditional_format("A2",
                             {"type": "formula",
                              "criteria": "=$B$2='y'",
                              "format": format1
                             }
)

None of this has given the expected result and when I open the file, I get an error with the following message: unreadable content in the .xlsx
Also it will be good if I could somehow set do this without iterating the dataframe's value.

Answer 1

Excel doesn't seem to like the single quotes for conditional formatting on a string. It works if you have the double quotes on the inside, i.e.

"criteria": '=($B$2="y")' 

versus

"criteria": "=($B$2='y')"

I've put a full reproducible example below with a screenshot of the solution.

import pandas as pd

df = pd.DataFrame({"Name": ["A", "B", "C"], "Status": ['y', 'n', 'yy']})

writer = pd.ExcelWriter('test.xlsx', engine='xlsxwriter')

df.to_excel(writer, sheet_name='Sheet1', index=False)


workbook  = writer.book
worksheet = writer.sheets['Sheet1']

format1 = workbook.add_format({"bg_color": "#669731"})

worksheet.conditional_format("A2",
                             {"type": "formula",
                              "criteria": '=($B$2="y")',
                              "format": format1
                             }
)

workbook.close()

If you want to set this conditional format for a range of say 1000 cells in the column this is possible using the code for the conditional format.

worksheet.conditional_format("A2:A1001",
                             {"type": "formula",
                              "criteria": '=(B2:B1001="y")',
                              "format": format1
                             }
)

If on the other hand you want to set multiple conditions over a range, the only way I think this would be possible is to use a for loop, writing each cell with the format that matches a condition. I've provided the example below and it's expected output. Notice that this is a bit of a cheat since it overwrites what has already been put in the cell, if it meets any of the three conditions.

import pandas as pd

df = pd.DataFrame({"Name": ["A", "B", "C"], "Status": ['y', 'n', 'yy']}) 
writer = pd.ExcelWriter('test.xlsx', engine='xlsxwriter') 
df.to_excel(writer, sheet_name='Sheet1', index=False) 

workbook  = writer.book 
worksheet = writer.sheets['Sheet1'] 

format1 = workbook.add_format({"bg_color": "#669731"})
format2 = workbook.add_format({"bg_color": "#FFFA22"})
format3 = workbook.add_format({"bg_color": "#A43829"})

for i in range (0, len(df)):
    if df['Status'].ix[i] == "y":
        worksheet.write(i+1, 0, df['Name'].ix[i], format1)
    elif df['Status'].ix[i] == "n":
        worksheet.write(i+1, 0, df['Name'].ix[i], format2)
    elif df['Status'].ix[i] == "yy":
        worksheet.write(i+1, 0, df['Name'].ix[i], format3)


workbook.close()