Fromisoformat: argument must be str

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The fromisoformat method is used to convert a string representing a date and time in ISO 8601 format into a datetime.datetime object in Python.

The argument passed to the fromisoformat method must be a string. If a different data type is passed, such as an integer or a float, a TypeError will be raised with the message “argument must be str”. This is because the fromisoformat method expects the argument to be a string representing a date and time in a specific format.

Here’s an example to demonstrate the usage of the fromisoformat method: 

import datetime

# Correct usage
date_string = "2022-12-31T23:59:59"
datetime_obj = datetime.datetime.fromisoformat(date_string)
print(datetime_obj)  # Output: 2022-12-31 23:59:59

# Incorrect usage
incorrect_date = 20221231235959
incorrect_datetime_obj = datetime.datetime.fromisoformat(incorrect_date)
# Raises TypeError: argument must be str

In the example above, we first pass a correct ISO 8601 formatted date string to the fromisoformat method, and it successfully converts it into a datetime.datetime object. However, in the incorrect usage, we pass an integer instead of a string, which raises a TypeError with the specified error message.

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