Python pandas with lambda apply difficulty

Question

I am running the following function but somehow struggling to have it take the length condition into account (the if part). It simply runs the first part if the function only:

stringDataFrame.apply(lambda x: x.str.replace(r'[^0-9]', '') if (len(x) >= 7) else x)

it somehow only runs the x.str.replace(r'[^0-9]', '') part for some reason, what am I doing wrong here i have been stuck.

x is a series, and len(x) is the length of that series. Do you want to check individual strings' lengths? — user2285236
– user2285236, Commented Aug 17, 2016 at 10:45

suteerthv · Accepted Answer · 2017-08-08 05:57:00Z

1

You can use applymap when you need to work on each value separately, because apply works with all column (Series).

Then instead of using str.replace, use re.sub which works nicer for regexs:

print (stringDataFrame.applymap(lambda x: re.sub(r'[^0-9]', '', x) if (len(x) >= 7) else x))

Sample:

import pandas as pd
import re

stringDataFrame = pd.DataFrame({'A':['gdgdg454dgd','147ooo2', '123ss45678'],
                                'B':['gdgdg454dgd','x142', '12345678a'],
                                'C':['gdgdg454dgd','xx142', '12567dd8']})

print (stringDataFrame)
             A            B            C
0  gdgdg454dgd  gdgdg454dgd  gdgdg454dgd
1      147ooo2         x142        xx142
2   123ss45678    12345678a     12567dd8

print (stringDataFrame.applymap(lambda x: re.sub(r'[^0-9]', '', x) if (len(x) >= 7) else x))
          A         B       C
0       454       454     454
1      1472      x142   xx142
2  12345678  12345678  125678

edited Aug 8, 2017 at 5:57

suteerthv

133 bronze badges

answered Aug 17, 2016 at 10:55

jezrael

868k103 gold badges1.4k silver badges1.3k bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Jeff Over a year ago

Thank you @jezrael this works. I had tried applymap but seems like the issue was with using str.replace

Jeff Over a year ago

Just a quick one which also falls within this question. I am horrible when it comes to lambda and functions. But i want to have two conditions by adding an additional x.contains("tel | cel | cell", case=False). This would then mean the formula should look something like this

stringDataFrame.applymap(lambda x: re.sub(r'[^0-9]', '', x) if ((len(x) >= 7) & (x.contains("tel | cel | cell", case=False))) else x)

@jezrael

jezrael Over a year ago

You need plain python, try

print (stringDataFrame.applymap(lambda x: re.sub(r'[^0-9]', '', x) if (len(x) >= 7) and (any(ext in x.lower() for ext in ['cel','tel','cell'])) else x))

Jeff Over a year ago

Thanks @jazrael i will iterate through the results

Collectives™ on Stack Overflow

Python pandas with lambda apply difficulty

1 Answer 1

4 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

4 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related