Pandas split on regex
Yes, split supports regex. According to your requirements,
split based on a regex match of a comma followed by a space and a capital letter
you may use
df['incident_characteristics'].str.split(r'\s*,\s*(?=[A-Z])', expand=True)
See the regex demo.
Details
\s*,\s*- a comma enclosed with 0+ whitespaces(?=[A-Z])- only if followed with an uppercase ASCII letter
However, it seems you also don't want to match the comma inside parentheses, add (?![^()]*\)) lookahead that fails the match if, immediately to the right of the current location, there are 0+ chars other than ( and ) and then a ):
r'\s*,\s*(?=[A-Z])(?![^()]*\))'
and it will prevent matching commas before capitalized words inside parentheses (that has no parentheses inside).
See another regex demo.
You can try .str.extractall (but I think there are better patterns than mine).
import pandas as pd
txt = 'Shot - Wounded/Injured, Shot - Dead (murder, accidental, suicide), Suicide - Attempt, Murder/Suicide, Attempted Murder/Suicide (one variable unsuccessful), Institution/Group/Business, Mass Murder (4+ deceased victims excluding the subject/suspect/perpetrator , one location), Mass Shooting (4+ victims injured or killed excluding the subject/suspect)'
df = pd.DataFrame({'incident_characteristics': [txt]})
df['incident_characteristics'].str.extractall(r'([\w\+\-\/ ]+(\([\w\+\-\/\, ]+\))?)')[0]
Output:
# match
# 0 0 Shot - Wounded/Injured
# 1 Shot - Dead (murder, accidental, suicide)
# 2 Suicide - Attempt
# 3 Murder/Suicide
# 4 Attempted Murder/Suicide (one variable unsucc...
# 5 Institution/Group/Business
# 6 Mass Murder (4+ deceased victims excluding th...
# 7 Mass Shooting (4+ victims injured or killed e...
# Name: 0, dtype: object
If you use .str.split, the first letter will be removed as it is used as a part of delimiter.
df['incident_characteristics'].str.split(r',\s[A-Z]', expand=True)
Output:
# 0 1 \
# 0 Shot - Wounded/Injured hot - Dead (murder, accidental, suicide)
# 2 3 \
# 0 uicide - Attempt urder/Suicide
# 4 \
# 0 ttempted Murder/Suicide (one variable unsucces...
# 5 \
# 0 nstitution/Group/Business
# 6 \
# 0 ass Murder (4+ deceased victims excluding the ...
# 7
# 0 ass Shooting (4+ victims injured or killed exc...