How to cast all objects to str in a pandas dataframe

Question

I want to change all columns of type object to str and I do not understand why this command does not work:

df.select_dtypes(include=["object"]) = df.select_dtypes(include=
["object"]).astype(str)

Answer 1

It does not work, because obviously object dtype is string.

You can test it by:

print (df.select_dtypes(include=["object"]).applymap(type))