pandas 1.0将一个字符串数据类型列替换为NANs

import pandas as pd

# 创建一个DataFrame
data = {'col1': ['apple', 'banana', 'orange', 'apple'],
        'col2': ['red', 'yellow', 'orange', 'green']}
df = pd.DataFrame(data)

# 将col1列中的字符串数据类型替换为NaNs
df['col1'] = df['col1'].replace('apple', pd.NA)

print(df)

    col1    col2
0    <NA>     red
1  banana  yellow
2  orange  orange
3    <NA>   green