Final answer:
To resolve the 'AttributeError: 'Series' object has no attribute 'strftime'', apply the strftime method individually to each date/time object within the pandas Series using the Series' apply method with a lambda function that handles non-null values.
Step-by-step explanation:
The AttributeError: 'Series' object has no attribute 'strftime' error occurs in Python when you're using pandas and you attempt to call the strftime method on a pandas Series object, instead of on a single datetime object. The strftime method is used to format date/time objects into readable strings. The pandas Series might be containing date/time data, but the method cannot be applied directly to the entire series. To solve this, you can use the apply method to call strftime on each individual date/time object within the series.
Here's an example of how you can apply strftime to each item in the series:
formatted_dates = your_series.apply(lambda x: x.strftime('%Y-%m-%d') if not pd.isnull(x) else x)
This line will create a new series where each date/time object in your_series is converted to a string formatted according to the specified format, for non-null values.