如何使用 xlsxwriter 格式化索引列？

Question

我正在使用 xlsxwriter 和 set_column 函数来格式化我的 excel 输出中的列。

但是，当应用于索引列（或多索引情况下的索引列）时，格式似乎被忽略了。

我找到了一种解决方法，到目前为止是使用 reset_index 引入一个假索引，然后将 index=False 传递给 to_excel 函数，然后是多索引也将消失。

有什么想法吗？

import pandas as pd
import numpy as np

from Config import TEMP_XL_FILE

def temp():
    ' temp'
    pdf = pd.DataFrame(np.random.randn(6,4), columns=list('ABCD'))
    pdf.set_index('A', drop=True, inplace=True)
    writer = pd.ExcelWriter(TEMP_XL_FILE, engine='xlsxwriter')
    pdf.to_excel(writer, 'temp')
    workbook = writer.book
    worksheet = writer.sheets['temp']
    tempformat = workbook.add_format({'num_format': '0%', 'align': 'center'})
    worksheet.set_column(-1, 3, None, tempformat)
    writer.save()

if __name__ == '__main__':
    temp()

Answer 1

pandas ExcelWriter 会覆盖索引列中的 XlsxWriter 格式。 为防止这种情况，请将熊猫 header_style 更改为 None

header_style = {"font": {"bold": True},
                "borders": {"top": "thin",
                            "right": "thin",
                            "bottom": "thin",
                            "left": "thin"},
                "alignment": {"horizontal": "center",
                              "vertical": "top"}} 

这样做：

import pandas.io.formats.excel

pandas.io.formats.excel.header_style = None

另见

• xlsxwriter not applying format to header row of dataframe - Python Pandas
• Pandas raising: AttributeError: module 'pandas.core' has no attribute 'format'

Answer 2

据我了解，Pandas 设置索引行的格式。有办法重置它，但这些解决方案不是很可靠。实际格式化也相当困难。

用所需格式写出索引列最适合我：

import pandas as pd

# The data that we're feeding to ExcelWriter
df = pd.DataFrame(
    {
        "Col A": ["a", "a", "b", "b"],
        "Col B": ["a", "b", "c", "d"],
        "Col C": [1, 2, 3, 4],
    }
)

# The Excel file we're creating
writer = pd.ExcelWriter("pandas_out.xlsx", engine="xlsxwriter")
df.to_excel(writer, sheet_name="Sheet1", index=False) # Prevents Pandas from outputting an index

# The variables we'll use to do our modifications
workbook = writer.book
worksheet = writer.sheets["Sheet1"]

worksheet.set_row(0, 30) # Set index row height to 30

# Find more info here: https://xlsxwriter.readthedocs.io/format.html#format-methods-and-format-properties
header_format = workbook.add_format(
    {
        "bold": True,
        "valign": "vcenter",
        "align": "center",
        "bg_color": "#d6d6d6",
        "border": True,
    }
)

# Write the column headers with the defined format.
for col_num, value in enumerate(df.columns.values):
    worksheet.write(0, col_num, value, header_format)

# Set format of data
format1 = workbook.add_format({"align": "center"})
worksheet.set_column('A:Z', 10, format1) # Width of cell

writer.save()

Answer 3

要添加到@Max 的答案，这对我来说适用于 pandas 1.1.5：

import pandas.io.formats.excel

pandas.io.formats.excel.ExcelFormatter.header_style = None

Answer 4

• 不要对库进行猴子补丁，从格式化程序类派生
• 不必费心重写所有代码来自己创建单元格
• 使用 Pandas 在内部为单元格内容定义的中间“类 CSS”格式化语言；这都写在pandas/io/excel/_xlsxwriter.py

这适用于 1.1.5：

import numpy as np
import pandas as pd
from pandas.io.formats.excel import ExcelFormatter
from typing import Dict, Any

# from Config import TEMP_XL_FILE
TEMP_XL_FILE = 'headers.xlsx'

class CenteredFormatter(ExcelFormatter):
    @property
    def header_style(self) -> Dict[str, Any]:
        d = dict(super().header_style)
        d.setdefault('alignment', {})['horizontal'] = 'center'
        d.setdefault('number_format', {})['format_code'] = '0%'
        return d


def temp() -> None:
    with pd.ExcelWriter(TEMP_XL_FILE, engine='xlsxwriter') as writer:
        pdf = pd.DataFrame(np.random.randn(6, 4), columns=list('ABCD'))
        pdf.set_index('A', drop=True, inplace=True)
        formatter = CenteredFormatter(pdf)
        formatter.write(writer, sheet_name='temp')

if __name__ == '__main__':
    temp()