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implosion

Sun Sep 27, 2009 3:31 pm


Help with satisfying conditions

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Hi there, i just started learning python and i'm having a bit of difficulty. This is purely beginning stuff but i can't seem to understand why the answer isn't correct.

Question: Given two variables,  is_empty of type  bool , indicating whether a class roster is empty or not, and  number_of_credits of type  integer , containing the number of credits for a class, write an expression that evaluates to  True if the class roster is not empty and the class is one or three credits.

[code]is_empty == False and number_of_credits == 1 or number_of_credits == 3[/code]

i'm using Wing IDE


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DtY

Sun Sep 27, 2009 3:58 pm


RE:Help with satisfying conditions

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Logical and binds higher than logical or, so say you have the expression

A and B or C
is identical to
(A and B) or C
Not
A and (B or C)

So, you need to use brackets to fix the order of operations,
[code]is_empty == False and (number_of_credits == 1 or number_of_credits == 3)[/code]

Also, it's not required at all, but when using and/or it's suggested you put brackets around each of the operands.
So,
(A == B) or (B == C)
instead of,
A == B or B == C
It just makes it look more clear.


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implosion

Sun Sep 27, 2009 4:08 pm


RE:Help with satisfying conditions

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oh okay. i see. thank you very much. The only other language i know is Turing. lol