Understanding the String Conversion of a Date with an English Month

In your Python 3.6.1 environment, the following coding seems to work well.

If the first argument of datetime.strptime('date','%d%b%Y') really remains 'date', it is treated as a string of atedate と instead of a variable.
Alternatively, : of the code provided is a full-width character, so is this mistaken for a half-width character?
If the code below does not solve this problem, it will be easier to get a more detailed answer if you add the error as it is.

>>>from datetime import datetime
>>>date="10 OCT 2017"
>> datetime.strptime (date, '%d%b%Y')
datetime.datetime (2017, 10, 10, 0, 0)
>>>date="date:10 OCT 2017"
>> datetime.strptime (date, 'date: %d %b %Y')
datetime.datetime (2017, 10, 10, 0, 0)