Lambda function error

[DeaD_EyE]

If this is the format: Jan 27, 2020 4:36:02 PM GMT+0000
This will be the format string for datetime: "%b %d, %Y %I:%M:%S %p %Z%z"

• %b: Month as locale’s abbreviated name.
  
• %d: Day of the month as a zero-padded decimal number.
  
• %Y: Year with century as a decimal number.
  
• %I: Hour (12-hour clock) as a zero-padded decimal number.
  
• %M: Minute as a zero-padded decimal number.
  
• %S: Second as a zero-padded decimal number.
  
• %p: Locale’s equivalent of either AM or PM.
  
• %Z: Time zone name (empty string if the object is naive).
  
• %z: UTC offset in the form ±HHMM[SS[.ffffff]] (empty string if the object is naive).
  

The method datetime.strptime will convert the string into a datetime object. The format is documented.

If the format is iso8601, it's much easier, because there is a method datetime.datetime.fromisoformat which parses this format specification.

from datetime import datetime as dt

my_format = "%b %d, %Y %I:%M:%S %p %Z%z"
my_timestamp = "Jan 27, 2020 4:36:02 PM GMT+0000"

# now use strptime, which is the abbreviation for "string put time",
# which is used to create a datetime object from str
# datetime.datetime.strptime(your_date, your_format)


# strftime means "string format time"
# which is used to convert datetime to a str


my_date = dt.strptime(my_timestamp, my_format)

ISO8601 example:

from datetime import datetime as dt


my_timestamp = "2020-01-29T14:12:53.439493+01:00"
my_date = dt.fromisoformat(my_timestamp)

In both cases the offset from utc is known. The resulting datetime-object has the timezone offset included.

Paring the ISO8601 timestamp manually is also possible, but not required.

from datetime import datetime as dt


iso8601_fmt = '%Y-%m-%dT%H:%M:%S%z'
ts = "2020-01-28T20:32:25+10:00"

my_date = dt.strptime(ts, iso8601_fmt)

Don't forget, that there are two different types datetime objects.

• datetime with timezone information
  
• naive datetime without timezone information
  

You can't do operations between a naive datetime and a datetime object.
For example you have a datetime object created, to compare it with your timestamps:

from datetime import datetime as dt


not_before = dt(2020, 1, 10) # no timezone
my_timestamp = dt.fromisoformat("2020-01-28T20:32:25+10:00")

if my_timestamp < not_before:
    print(f'{my_timestamp} is before {not_before}')
else:
    print(f'{my_timestamp} is not before {not_before}')

Error:
TypeError: can't compare offset-naive and offset-aware datetimes

To fix this problem with external dependencies:

from datetime import datetime as dt

# pip install pendulum
import pendulum

my_timezone = pendulum.timezone('Europe/Berlin')

not_before = my_timezone.datetime(2020, 1, 10)
my_timestamp = dt.fromisoformat("2020-01-28T20:32:25+10:00")

if my_timestamp < not_before:
    print(f'{my_timestamp} is before {not_before}')
else:
    print(f'{my_timestamp} is not before {not_before}')

To handle timezone direct with datetime is a bit annoying.
Depending on you input, you can decide what do to.