python syntax if in list function

user_6365890 0
Viewed 82

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?

pandas if-statement function python loops
2 Answers

Use np.where with pandas isin as:

df['flag'] = np.where(df['columnx'].isin([1,2,3,4,5]),'yes','no')
user_83208610

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"])
user_65773820
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