Programming Forums > Script Programming > Python

Dietrich · Jan 28th, 2006, 11:32 AM

Comparing two tuples gives expected result

print (1, 2) < (1, 3)  # True, makes sense

Similar thing with two lists

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print [1, 2] < [1, 3]  # True

Now a list and a tuple

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print [1, 2] < (1, 3)  # True, looks okay

Here comes the oops!

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print (1, 2) < [1, 3]  # False, oops!

Does anybody know the why?

Arevos · Jan 28th, 2006, 1:12 PM

Quote:

Originally Posted by Dietrich

Does anybody know the why?

It would appear that Python considers lists to always be "less than" tuples, no matter what the elements in the two objects:

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>>> [1, 2] < (0, 1)
True
>>> [1, 2] < (0,)
True

Likewise, the reverse applies; tuples are considered to be always "greater than" lists.

Dietrich · Jan 28th, 2006, 1:28 PM

Quote:

Originally Posted by Arevos

It would appear that Python considers lists to always be "less than" tuples, no matter what the elements in the two objects:

(Toggle Plain Text)

>>> [1, 2] < (0, 1)
True
>>> [1, 2] < (0,)
True

Likewise, the reverse applies; tuples are considered to be always "greater than" lists.

Thank you Arevos, that seems to be the interesting conclusion.
Moral, don't compare tuples (pears) with lists (apples)!

Sane · Jan 28th, 2006, 2:02 PM

Unless you convert either or with list()/tuple() >.>

^_^

Dietrich · Feb 5th, 2006, 2:34 PM

I will stop to be silly after this:
[PHP]# a mixed object list
list1 = [2, 1.99, [1, 2], (1, 2), {'c': 1, 'b': 2}, "bush"]

# sort/compare order seems to be numerics (float or integer), dictionary, list, string, tuple
print sorted(list1) # [1.99, 2, {'c': 1, 'b': 2}, [1, 2], 'bush', (1, 2)][/PHP]

Jan 28th, 2006, 11:32 AM	#1
Dietrich Professional Programmer Join Date: Feb 2005 Posts: 434 Rep Power: 4	Comparing Tuples and Lists Comparing two tuples gives expected result (Toggle Plain Text) print (1, 2) < (1, 3) # True, makes sense print (1, 2) < (1, 3) # True, makes sense Similar thing with two lists (Toggle Plain Text) print [1, 2] < [1, 3] # True print [1, 2] < [1, 3] # True Now a list and a tuple (Toggle Plain Text) print [1, 2] < (1, 3) # True, looks okay print [1, 2] < (1, 3) # True, looks okay Here comes the oops! (Toggle Plain Text) print (1, 2) < [1, 3] # False, oops! print (1, 2) < [1, 3] # False, oops! Does anybody know the why? __________________ I looked it up on the Intergnats!

Feb 5th, 2006, 2:34 PM	#5
Dietrich Professional Programmer Join Date: Feb 2005 Posts: 434 Rep Power: 4	I will stop to be silly after this: [PHP]# a mixed object list list1 = [2, 1.99, [1, 2], (1, 2), {'c': 1, 'b': 2}, "bush"] # sort/compare order seems to be numerics (float or integer), dictionary, list, string, tuple print sorted(list1) # [1.99, 2, {'c': 1, 'b': 2}, [1, 2], 'bush', (1, 2)][/PHP] __________________ I looked it up on the Intergnats!

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Jan 28th, 2006, 2:02 PM	#4
Sane Programming Guru Join Date: Apr 2005 Location: Waterloo, Ontario Posts: 1,885 Rep Power: 5	Unless you convert either or with list()/tuple() >.> ^_^

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Programming Forums > Script Programming > Python

Comparing Tuples and Lists