strptime() argument 1 must be str, not Series

This error occurs when the input argument to the `strptime()` function is a pandas Series object instead of a string object.

To fix this error, you can convert the Series object to a string using the `str()` method before passing it to the `strptime()` function.

For example:

import pandas as pd
from datetime import datetime

# create a pandas Series object
dates = pd.Series(['2022-01-01', '2022-01-02'])

# convert Series to string using str() method
date_str = dates.str[0]

# use strptime() function with string input
date_obj = datetime.strptime(date_str, '%Y-%m-%d')

In this example, we first extract the first element of the Series using the `.str[0]` method, which returns a string. We then pass this string to the `strptime()` function to convert it to a datetime object.