Answers for "info() function in pandas only show one column yet I have many columns"

how many columns can a pandas dataframe have

You get an out of memory error because you run out of memory, not because there is a limit on the number of columns.

pandas count show one column

# You can – optionally – remove the unnecessary columns and 
# keep the user_id column only:

article_read.groupby('source').count()[['user_id']]

# Change user_id as you see fit.