Python Dataframe：DF列中的字符串包含来自不同DF的子字符串和匹配时返回的子字符串值

Question

同事们，

也许你可以帮助我完成看似简单的任务，但我还没有足够的经验来解决这个问题。

假设我们有两个数据框：

1. df1 包含子字符串；
2. df2 包含较长的文本块，其中一些包含来自 df1 的子字符串。

df1 = {'subst': ['LONDON BRIDGE', 'TRUE GRIT', 'FIVE TIMES FIVE', 'THREE TIME DEAD', 'TRUE IS NOT', 'OH NO', 'LEBRON JAMES']}

df2 = {'strng': ['LEBRON JAMES SCORED 20', 'THREE TIMES DEAD JOHNY WAS HELL OF THE COOK', 'TRUE IS NOT WHAT YOU THINK', 'FIVE TIMES FIVE IS NOT WHAT LEBRON SCORED']}

df1 = pd.DataFrame(df1)
df2 = pd.DataFrame(df2)

这是我需要的：

1. 我需要遍历行以检查 df1['subst'] 中的子字符串是否存在于 df2['strng'] 中的任何位置
2. 如果它存在于 df2 中，我希望 df2 中的新列 ['match_df1'] 包含来自 df1 的子字符串值。

df2 中的最终输出看起来像这样

strng	match_df1
LEBRON JAMES SCORED 20	LEBRON JAMES
THREE TIMES DEAD JOHNY WAS HELL OF THE COOK	THREE TIMES DEAD
TRUE IS NOT WHAT YOU THINK	TRUE IS NOT
FIVE TIMES FIVE IS NOT WHAT LEBRON SCORED	FIVE TIMES FIVE

Answer 1

正如@Chris 所注意到的，这个answer 可能会完成这项工作。
然后像这样过滤空字符串：

>>> for ind1 in df1.index:
...    df1.loc[ind1, 'strng'] = ', '.join(list(df2[df2['strng'].str.contains(df1['subst'][ind1])]['strng']))
>>> df1[df1['strng'].str.len() > 0]
    subst                strng
2   FIVE TIMES FIVE      FIVE TIMES FIVE IS NOT WHAT LEBRON SCORED
4   TRUE IS NOT          TRUE IS NOT WHAT YOU THINK
6   LEBRON JAMES         LEBRON JAMES SCORED 20

所有代码：

import pandas as pd

df1 = {'subst': ['LONDON BRIDGE', 'TRUE GRIT', 'FIVE TIMES FIVE', 'THREE TIME DEAD', 'TRUE IS NOT', 'OH NO', 'LEBRON JAMES']}
df2 = {'strng': ['LEBRON JAMES SCORED 20', 'THREE TIMES DEAD JOHNY WAS HELL OF THE COOK', 'TRUE IS NOT WHAT YOU THINK', 'FIVE TIMES FIVE IS NOT WHAT LEBRON SCORED']}

df1 = pd.DataFrame(df1)
df2 = pd.DataFrame(df2)

for ind1 in df1.index:
   df1.loc[ind1, 'strng'] = ', '.join(list(df2[df2['strng'].str.contains(df1['subst'][ind1])]['strng']))
df1[df1['strng'].str.len() > 0]