Can't drop NAN with dropna in pandas

Question

I import pandas as pd and run the code below and get the following result

Code:

traindataset = pd.read_csv(\'/Users/train.csv\')
print traindataset.d         


        

Answer 1

This is my first post. I just spent a few hours debugging this exact issue and I would like to share how I fixed this issue.

I was converting my entire dataframe to a string and then placing that value back into the dataframe using similar code to what is displayed below: (please note, the code below will only convert the value to a string)

row_counter = 0
for ind, row in dataf.iterrows():
    cell_value = str(row['column_header'])
    dataf.loc[row_counter, 'column_header'] = cell_value
    row_counter += 1

After converting the entire dataframe to a string, I then used the dropna() function. The values that were previously NaN (considered a null value by pandas) were converted to the string 'nan'.

In conclusion, drop blank values FIRST, before you start manipulating data in the CSV and converting its data type.