如何拆分DataFrame中含列表格式字符串的列并扩展对应行？

现有一个DataFrame，其中actor列的值是列表格式的字符串，示例代码如下：

import pandas as pd

actor = ["[Emil Eifrem,Hugo Weaving,Laurence Fishburne]"]
title = ["The Matrix"]

actors = pd.DataFrame(list(zip(actor, title)),
                      columns = ["actor", "title"])

我们需要将actor列的列表字符串拆分为独立元素，同时让title列对应重复多次，最终得到如下结构的DataFrame：

actor = ["Emil Eifrem", "Hugo Weaving", "Laurence Fishburne"]
title = ["The Matrix"] * 3

actors = pd.DataFrame(list(zip(actor, title)),
                      columns = ["actor", "title"])

解决方案 #

通过两步操作即可实现需求：

1. 将列表格式的字符串转换为真实的列表对象
2. 使用explode方法将列表列展开为多行，自动重复对应行的其他列值

完整代码

import pandas as pd

actor = ["[Emil Eifrem,Hugo Weaving,Laurence Fishburne]"]
title = ["The Matrix"]

actors = pd.DataFrame(list(zip(actor, title)),
                      columns = ["actor", "title"])

# 清洗字符串，转换为列表
actors['actor'] = actors['actor'].str.strip('[]').str.split(',')
# 展开列表列，重置索引
actors = actors.explode('actor', ignore_index=True)

# 查看最终结果
print(actors)

输出结果

actor        title
0       Emil Eifrem  The Matrix
1       Hugo Weaving  The Matrix
2  Laurence Fishburne  The Matrix

内容的提问来源于stack exchange，提问作者Salahuddin