在字符分隔符上将字符串（对象）拆分为两列，但 KEEP 字符分隔符

Question

In pandas, I am trying to split a column into two columns on a character and want to keep the character delimiter.

I have tried str.split() and it splits the columns the way I want but it deletes the character delimiter (as it is supposed to).

My column looks like this.

   mor
0  HR Ncfsa 

I am using this code:

df[['mor1', 'mor2']] = df['mor'].str.split(pat='^[A-Z]', n=-1, expand=True)

I get

   mor1   mor2
0         R Ncfsa

But I want to keep the first letter of the original column to get:

   mor1   mor2
0  H      R Ncfsa

Answer 1

IIUC, use Series.str.extract

df['mor'].str.extract('^(?P<mor1>[A-Z])(?P<mor2>.*)$')

[out]

  mor1     mor2
0    H  R Ncfsa