Haing this error :

The call str$\_$to$\_$time$(\text{'}2016-05-12$T$16$:$23-4$:$00\text{'},$ datetime.datetime$(2016,5,12,16,23,$ tzinfo$=))$ returns datetime.datetime$(2016,5,12,16,23,$ tzinfo$=),$ not datetime.datetime$(2016,5,12,16,23,$ tzinfo$=).$

On this python def

def str$\_$to$\_$time$($timestamp$,$tzsource$=$None$)$:

$"""$

Returns the datetime object for the given timestamp $($or None if timestamp is

invalid$).$

This function should just use the parse function in dateutil.parser to

convert the timestamp to a datetime object. If it is not a valid date $($so

the parser crashes$),$ this function should return None.

If the timestamp has a time zone, then it should keep that time zone even if

the value for tzsource is not None. Otherwise, if timestamp has no time zone

and tzsource is not None, then this function will use tzsource to assign

a time zone to the new datetime object.

The value for tzsource can be None, a string, or a datetime object. If it

is a string, it will be the name of a time zone, and it should localize the

timestamp. If it is another datetime, then the datetime object created from

timestamp should get the same time zone as tzsource.

Parameter timestamp: The time stamp to convert

Precondition: timestamp is a string

Parameter tzsource: The time zone to use $($OPTIONAL$)$

Precondition: tzsource is either None, a string naming a valid time zone,

or a datetime object.

$"""$

# HINT: Use the code from the previous exercise and add time zone handling.

# Use localize if tzsource is a string; otherwise replace the time zone if not None

try:

dt $=$ parser.parse$($timestamp$)$

except ValueError:

return None

if tzsource is None:

return dt

if hasattr$($tzsource$,$ 'tzinfo'$)$ and tzsource.tzinfo is not None:

return dt$.$replace$($tzinfo$=$tzsource.tzinfo$)$

elif isinstance$($tzsource$,$ str$)$:

time$\_$zone $=$ pytz$.$timezone$($tzsource$)$

return time$\_$zone.localize$($dt$)$

else:

return dt