python syntax if in list function

Question

I am trying to find the proper python syntax to create a flag with a value of yes if columnx contains any of the following numbers: 1, 2, 3, 4, 5.

def create_flag(df):
    if df['columnx'] in (1,2,3,4,5):
        return df['flag']=='yes'

I get the following error.

TypeError: invalid type comparison

Is there an obvious mistake in my syntax?

Python is both case and space sensitive. The code you posted will raise a syntax error before it gets to type error. — Mad Physicist
– Mad Physicist, Commented Oct 31, 2018 at 6:36

Space Impact · Accepted Answer · 2018-10-31 06:18:49Z

2

Use np.where with pandas isin as:

df['flag'] = np.where(df['columnx'].isin([1,2,3,4,5]),'yes','no')

answered Oct 31, 2018 at 6:18

Space Impact

13.3k26 silver badges51 bronze badges

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

2 Comments

pynewbee Over a year ago

TypeError: isin() takes 2 positional arguments but 4 were given is the error i get

Space Impact Over a year ago

@pynewbee can you please check the syntax inside isin whether you have given list as [1,2,3,4,5] or something else.

Anagnostou John · Accepted Answer · 2018-10-31 06:33:19Z

0

You have lot of problems in your code! i assume you want to try something like this

def create_flag(df):
    if df['columnx'] in [1,2,3,4,5]:
        df['flag']='yes'

x = {"columnx":2,'flag':None}

create_flag(x)
print(x["flag"])

answered Oct 31, 2018 at 6:33

Anagnostou John

5145 silver badges15 bronze badges

Collectives™ on Stack Overflow

python syntax if in list function

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related