Page 2 - Checking for valid date input and convert appropriately

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#16

February 22nd, 2013, 07:27 AM

Nik

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Location: Thessaloniki

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Let me ask it like this:
How can i avoid using try: except: for checkign the date but instead check it with an if statement:

Code:

if ( datetime.strptime(date, '%d %m %Y') ): 
     date = datetime.strptime(date, '%d %m %Y').strftime('%Y-%m-%d') 
else: 
     print( "Date wasn't entered properly" )

I'am trying this but if user entered date is noit on the acceptible format it raises an exception.
If i surround it with eval() its still raises an excpetion.

Code:

if ( eval( datetime.strptime(date, '%d %m %Y')  ) ): 
     date = datetime.strptime(date, '%d %m %Y').strftime('%Y-%m-%d') 
else: 
     print( "Date wasn't entered properly" )

How can i write that with an if suppresing the errors if any?

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#17

February 22nd, 2013, 08:53 AM

SuperOscar

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Quote:

Originally Posted by Nik

Let me ask it like this:
How can i avoid using try: except: for checkign the date but instead check it with an if statement:

Well it’s possible but demands lots of extra work. First you create a function to do sanity checks:

Code:

def is_sane_date(date):
    parts = [int(part) for part in date.split() if part.isdigit()]
    if len(parts) == 3 and \
         1 <= parts[0] <= 31 and \
         1 <= parts[1] <= 12 and \
         1900 <= parts[2] <= 2100:
        return True
    return False

And then you use this in your if test:

Code:

if is_sane_date(date):
    # ...

But exceptions are there for a purpose!

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#18

February 22nd, 2013, 09:07 AM

Nik

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Join Date: Jun 2003

Location: Thessaloniki

Posts: 1,004

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ok, i'll just use the try: except: i was just thinking putting them all in the same if() statemt but apparently it can't be done without creatign extra functions!

thank you!

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