How to print a row in Pandas dataframe by its numerical index after assigning names to columns?

In the following code I get a “KeyError: 0”.

import pandas as pd
import math

data = pd.read_csv(…) #file name and other parameters

data.columns=['UNIX_UTC_Time', 'Home_Team', …] #columns names

matches_number=len(data.index)

def check_data_quality():
    for x in range (matches_number):
        for y in range (11): #number of columns
            if y==1 or y==2: #these columns are strings
                continue     
            if math.isnan(data.at[x,y]):
                print('NaN in:',data.at[x,y],'row',data.iloc[x])

check_data_quality()

Using loc instead of iloc doesn't help either.

If I remove data.columns line, then everything works.

Please let me know how I can print (whole) rows with unintended NaNs here.

Thank you!