How to rearrange the df the following format in python?

Question

i have a dataframe

df =  pd.Dataframe({'date':["2022-01-01","2022-01-01","2022-01-02","2022-01-02"], 
                    'col1': ["a","b","a","b"],
                    'val': [1,2,3,4]
                   })

i want to transform my dataframe into

df =  pd.Dataframe({'date':["2022-01-01","2022-01-02"], 
                        'a': [1,3],
                        'b': [2,4],
                       })