Python Dataframe Conditional If Statement Using pd.np.where Erroring Out

Question

I have the following dataframe:

count   country year    age_group   gender  type
7       Albania 2006    014         f       ep
1       Albania 2007    014         f       ep
3       Albania 2008    014         f       ep
2       Albania 2009    014         f       ep
2       Albania 2010    014         f       ep

I'm trying to make adjustments to the "gender" column so that 'f' becomes 'female' and same for m and male.

I tried the following code:

who3['gender'] = pd.np.where(who3['gender'] == 'f', "female")

But it gives me this error:

Now when I try this code:

who3['gender'] = pd.np.where(who3['gender'] == 'f', "female", 
                 pd.np.where(who3['gender'] == 'm', "male"))

I get error below:

What am I doing wrong?

Answer 1

You can use also .replace():

df["gender"] = df["gender"].replace({"f": "female", "m": "male"})
print(df)

Prints:

   count  country  year  age_group  gender type
0      7  Albania  2006         14  female   ep
1      1  Albania  2007         14  female   ep
2      3  Albania  2008         14  female   ep
3      2  Albania  2009         14  female   ep
4      2  Albania  2010         14  female   ep

Answer 2

np.where needs the condition as the first parameter, and then the desire output if the condition is met, and as the third parameter it gets an output when the condition is not met, Try this:

who3['gender'] = np.where(who3['gender'] == 'f', "female", 'male')

Another solution is using replace method:

who3['gender'] = who3['gender'].replace({'f': 'female', 'm': 'male'})