基于自定义列表从Pandas DataFrame中提取指定字符串

原始数据 #

import pandas as pd
df = pd.DataFrame({'a': ['hair color other family, friends ', 'family, friends hair color']})

对应的DataFrame：

自定义提取列表 #

items = ['hair color', 'other', 'family, friends']

期望输出 #

import numpy as np
desired_output = pd.DataFrame({
    'a': ['hair color other family, friends ', 'family, friends hair color'],
    'hair color': ['hair color', 'hair color'],
    'other': ['other', np.nan],
    'family, friends': ['family, friends', 'family, friends']
})

对应的DataFrame：

解决方案 #

直接通过遍历自定义列表，结合字符串包含检查生成新列：

import pandas as pd
import numpy as np

df = pd.DataFrame({'a': ['hair color other family, friends ', 'family, friends hair color']})
items = ['hair color', 'other', 'family, friends']

for item in items:
    df[item] = df['a'].apply(lambda x: item if item in x else np.nan)

# 查看结果
print(df)

说明 #

• 对每个自定义元素，创建同名新列
• 用apply遍历每行数据，判断元素是否存在于当前字符串中：存在则返回元素本身，不存在则填充NaN

内容的提问来源于stack exchange，提问作者johnjohn