如果一行包含特定字符串，pandas 是否可以在新列中创建一个整数

Question

For example, I have the following dataframe:

I want to transform the dataframe from above to something like this:

Thank's for any kind of help!

Answer 1

跑：

df['Number'] = df.svn_changes.str.match(r'r\d+').cumsum()

Answer 2

Yes, is contains with regex and cumsum :

df = pd.DataFrame({'svn_changes':['r123456','RowValueRow','ValueRowValue',
                                  'some_string_string','r234566','ValueRowValue',
                                  'some_string_string','r123789','something_here',
                                  'ValueRowValue','String_2','String_4']})

df['Number'] = df['svn_changes'].str.contains('r\d+').cumsum()
print(df)

Output:

           svn_changes  Number
0              r123456       1
1          RowValueRow       1
2        ValueRowValue       1
3   some_string_string       1
4              r234566       2
5        ValueRowValue       2
6   some_string_string       2
7              r123789       3
8       something_here       3
9        ValueRowValue       3
10            String_2       3
11            String_4       3

Answer 3

Here's a simple reusable line you can use to do that:

df['new_col'] = df['old_col'].str.contains('string_to_match')*1

The new column will have value 1 if the string is present in this column, and 0 otherwise.