I am changing data type in python.
First, my dataset look like:

I checked the dataset type of each column:
Then when I want to convert the dataset with this code:
df_tr = df1_dlq_slice.replace({'C': -1, 'F': -2, 'Z': -3}).astype(int).T
df_tr.head()
ValueError: invalid literal for int() with base 10: ' ' happened.
