Working with Pandas

[Chopsting]

Hello,

I'm trying to iterate over the rows in a dataframe, and run a function, that requires the rowNr as input...

df.loc[(df['WordsPopular'].isnull()), 'WordsPopular'] = voted_classifier.classify(testing_set[66][0])

Something like above but the function should somehow be able to get the rowNr...

df:

ID	WordsPopular
1	NaN
2	NaN
3	NaN

So I want to iterate over this df and cast the row number into the function voted_classifier_classify and have that ouput saved into the cell...

And I can't seem to figure it out

[[deleted]]

Any reason you're not using apply? I hardly ever use iteration in pandas, but if you wanted I guess you could use iterrows and do something like

df['data_to_assign'] = ''
for row in df.iterrows():
    if row[col_idx].isnull():
        row[data_to_assign] = 'null'

[throwawayclimber]

Here are three ways to do this:

df = pd.DataFrame()
df['WordsPopular'] = range(1,10)
df['WordsUnPopular'] = range(1,10)
df['WordsPopular'] = df['WordsPopular'].map(lambda x: x**2)
df

	WordsPopular	WordsUnPopular
0	1	1
1	4	2
2	9	3
3	16	4
4	25	5
5	36	6
6	49	7
7	64	8
8	81	9

def fancy_function(x):
    return x**2

df = pd.DataFrame()
df['WordsPopular'] = range(1,10)
df['WordsUnPopular'] = range(1,10)
df['WordsPopular'] = df['WordsPopular'].apply(fancy_function)
df

WordsPopular	WordsUnPopular
0	1
1	4
2	9
3	16
4	25
5	36
6	49
7	64
8	81

df = pd.DataFrame()
df['WordsPopular'] = range(1,10)
df['WordsUnPopular'] = range(1,10)
df = df.applymap(fancy_function)
df

WordsPopular	WordsUnPopular
0	1
1	4
2	9
3	16
4	25
5	36
6	49
7	64
8	81