将包含字典的dataframe单元格转换为包含新列的dataframe

import pandas as pd

# 创建示例DataFrame
df = pd.DataFrame({'col1': [{'key1': 'value1', 'key2': 'value2'}, {'key1': 'value3', 'key2': 'value4'}],
                   'col2': [{'key3': 'value5', 'key4': 'value6'}, {'key3': 'value7', 'key4': 'value8'}]})
print(df)

                   col1                  col2
0  {'key1': 'value1', 'key2': 'value2'}  {'key3': 'value5', 'key4': 'value6'}
1  {'key1': 'value3', 'key2': 'value4'}  {'key3': 'value7', 'key4': 'value8'}

# 定义转换函数
def transform_dict(cell):
    return cell['key1']

# 使用apply函数将每个单元格中的字典转换为新的列
df['new_col'] = df['col1'].apply(transform_dict)
print(df)

                   col1                  col2  new_col
0  {'key1': 'value1', 'key2': 'value2'}  {'key3': 'value5', 'key4': 'value6'}  value1
1  {'key1': 'value3', 'key2': 'value4'}  {'key3': 'value7', 'key4': 'value8'}  value3