python - How to extract a word before another word in pandas

Question

I've got this pandas DataFrame, which is a description of plays during a football match:

play_id	type	Text
1	pass	Jon pass complete to Ben.
2	pass	Clock 14:52, Jon pass complete to Mitch.
3	rush	Frank rush.

question from:https://stackoverflow.com/questions/66049688/how-to-extract-a-word-before-another-word-in-pandas

Answer 1

• Use pandas.Series.str.extract with a positive lookahead conditional.
  • See SO: Regex lookahead, lookbehind and atomic groups for a thorough explanation of lookahead.
  • s+pass will work for any amount of whitespace between the name and 'pass' (e.g. 'Jon PaSs')
• flags=re.IGNORECASE is used to ignore the case of 'pass'
  • df.Text.str.lower().str.extract('(w+(?=s+pass))') can be used instead of importing re for the flag.

import pandas as pd
import re

# test dataframe
data = {'play_id': ['1', '2', '3'], 'type': ['pass', 'pass', 'rush'], 'Text': ['Jon PASS complete to Ben.', 'Clock 14:52, Jon pass complete to Mitch.', 'Frank rush.']}
df = pd.DataFrame(data)

# display(df)
play_id type                                     Text
      1 pass                Jon PASS complete to Ben.
      2 pass Clock 14:52, Jon pass complete to Mitch.
      3 rush                              Frank rush.

# extract
df['passer'] = df.Text.str.extract('(w+(?=s+pass))', flags=re.IGNORECASE)

# display(df)
play_id type                                     Text passer
      1 pass                Jon PASS complete to Ben.    Jon
      2 pass Clock 14:52, Jon pass complete to Mitch.    Jon
      3 rush                              Frank rush.    NaN