Python 如何优化成为每列红色标记的前三名数据

发布于07月26日

这是使红色标记的每列中的最大值的代码.

import pandas as pd

def highlight_max(s):
    '''
    highlight the maximum in a Series yellow.
    '''
    is_max = s == s.max()
    return ['color: red' if v else '' for v in is_max]


writer = pd.ExcelWriter(f"after.xlsx", engine="xlsxwriter")
df = pd.read_excel('test.xlsx')
df.style.apply(highlight_max).to_excel(writer, index=False)
writer.save()

如何优化代码，使每列的前三个数据都用红色标记？

推荐答案

IIUC，您只需修改函数中定义的布尔掩码is_max.

可能的代码:

import pandas as pd
import numpy as np

df = pd.DataFrame({
    "x1": np.random.randint(0, 100, size=(25,)),
    "x2": np.random.randint(0, 100, size=(25,)),
    "x3": np.random.randint(0, 100, size=(25,)),
    "x4": np.random.randint(0, 100, size=(25,))
})

def highlight_ngreatest(s: pd.Series, n: int = 3):
    """
    Highlight N greatest values in a Series red.
    """
    is_n_greatest = s.isin(s.nlargest(n))
    return ["color: red" if v else "" for v in is_n_greatest]

df.style.apply(highlight_ngreatest, n=3)

输出: