Convert float64 column to int64 in Pandas

Question

I tried to convert a column from data type float64 to int64 using:

df[\'column name\'].astype(int64)

but got an e

Answer 1

This seems to be a little buggy in Pandas 0.23.4?

If there are np.nan values then this will throw an error as expected:

df['col'] = df['col'].astype(np.int64)

But doesn't change any values from float to int as I would expect if "ignore" is used:

df['col'] = df['col'].astype(np.int64,errors='ignore') 

It worked if I first converted np.nan:

df['col'] = df['col'].fillna(0).astype(np.int64)
df['col'] = df['col'].astype(np.int64)

Now I can't figure out how to get null values back in place of the zeroes since this will convert everything back to float again:

df['col']  = df['col'].replace(0,np.nan)