How to show all of columns name on pandas dataframe?

Question

I have a dataframe that consist of hundreds of columns, and I need to see all column names.

What I did:

In[37]:
data_all2.columns

T

Answer 1

I had lots of duplicate column names, and once I ran

df = df.loc[:,~df.columns.duplicated()]

I was able to see the full list of columns

Credit: https://stackoverflow.com/a/40435354/5846417