python - 在 Python 中搜索特定长度的相同字符串

Question

我有一个关于包含带有字符串的“文本”列的大型数据集的问题。我的目标是在 Python 中搜索至少 20 个字符的相同字符串。因此，我需要的数据集包含所有这些相同的字符串。
例如以下名为 df 的数据集:

  idnr       text 

      1      This sentence is more than 20 characters long
      2      Shorter sentence
      3      Short
      4      Short
      5      This sentence is more than 20 characters long
      6      Shorter sentence
      7      This sentence is more than 20 characters long
      8      Shorter sentence
      9      Short
     10      This sentence is more than 20 characters long
     11      This sentence is more than 20 characters long
     12      Shorter sentence

输出应该是:

  idnr       text 

      1      This sentence is more than 20 characters long
      5      This sentence is more than 20 characters long
      7      This sentence is more than 20 characters long
     10      This sentence is more than 20 characters long
     11      This sentence is more than 20 characters long

我可以在 Python 中使用什么脚本？

Answer 1

您可以按 Series.str.len 过滤行与更大的喜欢 20由 Series.duplicated 链接对于 2 个或更多值:

df1 = df[df['text'].str.len().gt(20) & df['text'].duplicated(keep=False)]

print (df1)
    idnr                                           text
0      1  This sentence is more than 20 characters long
4      5  This sentence is more than 20 characters long
6      7  This sentence is more than 20 characters long
9     10  This sentence is more than 20 characters long
10    11  This sentence is more than 20 characters long

测试可以使用:

m1 = df['text'].str.len().gt(20)
m2 = df['text'].duplicated(keep=False)
m3  = df['text'].str.len().gt(20) & df['text'].duplicated(keep=False)

print (df.assign(m1=m1, m2=m2, both=m3))
    idnr                                           text     m1    m2   both
0      1  This sentence is more than 20 characters long   True  True   True
1      2                               Shorter sentence  False  True  False
2      3                                          Short  False  True  False
3      4                                          Short  False  True  False
4      5  This sentence is more than 20 characters long   True  True   True
5      6                               Shorter sentence  False  True  False
6      7  This sentence is more than 20 characters long   True  True   True
7      8                               Shorter sentence  False  True  False
8      9                                          Short  False  True  False
9     10  This sentence is more than 20 characters long   True  True   True
10    11  This sentence is more than 20 characters long   True  True   True
11    12                               Shorter sentence  False  True  False