Python Pandas lambda function to change all the values of a column?

Question

I have the following data frame:

AIRCRAFT
B738 (C-GKWJ)
A321 (C-FJNX)

and using this code to extract only TYPE,

def extract_type(aircraft):
    return aircraft.split(" ")[0]

data['TYPE'] = data['AIRCRAFT'].apply(lambda x: extract_type(x))

my expectation is:

AIRCRAFT       TYPE
B738 (C-GKWJ)  B738
A321 (C-FJNX)  A321

but im getting:

AIRCRAFT       TYPE
B738 (C-GKWJ)  B738 (C-GKWJ)
A321 (C-FJNX)  A321 (C-FJNX)

when testing extract_type function, it works fine

 def extract_type(aircraft):
     return aircraft.split(" ")[0]

    extract_type("B737 (C-GWJT)")

returns 'B737'

Why it doesn't work with data frame and lambda function? Thanks

Vaishali · Accepted Answer · 2017-09-04 01:07:57Z

2

You can use str.split

data['TYPE'] = data['AIRCRAFT'].str.split().str[0]

You get

    AIRCRAFT    TYPE
0   B738 (C-GKWJ)   B738
1   A321 (C-FJNX)   A321

You can also use str.extract though split is ideal

 data['TYPE'] = data['AIRCRAFT'].str.extract('(\w+)\s\(', expand = False)

answered Sep 4, 2017 at 1:07

Vaishali

38.5k5 gold badges62 silver badges88 bronze badges

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

1 Comment

Glad that it worked. You can accept the answer if the issue is completely resolved