replace multiple strings in dataframe (Python / Pandas)

Question

I have the below including in a script and I'm sure there must be a better way to code this. Perhaps referring to two lists, reducing the number of lines. This is two different data frames but the replaced text is the same across both, so again could both df be referenced in the same line?

df_Final_hours = df_Final_hours.replace('Monday', 'Mon', regex=True)
df_Final_hours = df_Final_hours.replace('Tuesday', 'Tue', regex=True)
df_Final_hours = df_Final_hours.replace('Wednesday', 'Wed', regex=True)
df_Final_hours = df_Final_hours.replace('Thursday', 'Thu', regex=True)
df_Final_hours = df_Final_hours.replace('Friday', 'Fri', regex=True)
df_Final_hours = df_Final_hours.replace('Saturday', 'Sat', regex=True)
df_Final_hours = df_Final_hours.replace('Sunday', 'Sun', regex=True)

df_Final_traffic = df_Final_traffic.replace('Monday', 'Mon', regex=True)
df_Final_traffic = df_Final_traffic.replace('Tuesday', 'Tue', regex=True)
df_Final_traffic = df_Final_traffic.replace('Wednesday', 'Wed', regex=True)
df_Final_traffic = df_Final_traffic.replace('Thursday', 'Thu', regex=True)
df_Final_traffic = df_Final_traffic.replace('Friday', 'Fri', regex=True)
df_Final_traffic = df_Final_traffic.replace('Saturday', 'Sat', regex=True)
df_Final_traffic = df_Final_traffic.replace('Sunday', 'Sun', regex=True)

Matt

Does it need to be a regex? That is, do you need to replace substrings, or are you replacing whole values with whole values? — creanion, Jun 23 '22 at 19:51

score 2 · Answer 1 · answered Jun 23 '22 at 19:54

make use of the map

If you post the data, it'll be easier to present the solution. but, here is the idea

df_Final_hours[COLUMN_NAME].map(
    {'Monday':'Mon',
     'Tuesday':'Tue',
     'Wednesday': 'Wed',
     'Thursday' : 'Thu',
     'Friday' : 'Fri',
     'Saturday' : 'Sat',
     'Sunday' : 'Sun'
    })

score 0 · Accepted Answer · answered Jun 23 '22 at 20:00

You can create a dict containing the changes and then use the replace method you already used:

changes = {'Monday' : 'Mon',
           'Tuesday': 'Tue',
           'Wednesday': 'Wed',
           'Thursday': 'Thu',
           'Friday': 'Fri',
           'Saturday': 'Sat',
           'Sunday': 'Sun'}

df_Final_hours = df_Final_hours.replace(changes, regex=True)
df_Final_traffic = df_Final_traffic.replace(changes, regex=True)

score 0 · Answer 3 · answered Jun 23 '22 at 20:03

you can create a dictionary like this:

weekAbrvs= {
  "Monday": "Mon",
  "Tuesday": "Tues",
  "Wednesday": "Wed"
}

then you can do one for loop that changes/sets both df_Final_hours and df_Final_traffic
so something like this:

for key,value in weekAbrvs.items():
  df_Final_hours = df_Final_hours.replace(key, value, regex=True)
  df_Final_traffic = df_Final_traffic.replace(key, value, regex=True)

check this out: Iterating over dictionaries using 'for' loops

score 0 · Answer 4 · answered Jun 23 '22 at 20:14

0

You can import calendar create a dictionary then use replace with regex=True:

import calendar
d = dict(zip(calendar.day_name, calendar.day_abbr))
df.replace(d, regex=True)

answered Jun 23 '22 at 20:14

Scott Boston

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replace multiple strings in dataframe (Python / Pandas)

4 Answers4