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pythonif-statementsyntax

Putting an if-elif-else statement on one line?

Is there an easier way of writing an if-elif-else statement so it fits on one line?
For example,

if expression1:
    statement1
elif expression2:
    statement2
else:
    statement3

Or a real-world example:

if i > 100:
    x = 2
elif i < 100:
    x = 1
else:
    x = 0

I just feel if the example above could be written the following way, it could look like more concise.

x = 2 if i>100 elif i<100 1 else 0   # [WRONG]

I have read the link below, but it doesn't address my question.

Solution

  • No, it's not possible (at least not with arbitrary statements), nor is it desirable. Fitting everything on one line would most likely violate PEP-8 where it is mandated that lines should not exceed 80 characters in length.

    It's also against the Zen of Python: "Readability counts". (Type import this at the Python prompt to read the whole thing).

    You can use a ternary expression in Python, but only for expressions, not for statements:

    >>> a = "Hello" if foo() else "Goodbye"

    Edit:

    Your revised question now shows that the three statements are identical except for the value being assigned. In that case, a chained ternary operator does work, but I still think that it's less readable:

    >>> i = 100
>>> x = 2 if i>100 else 1 if i<100 else 0
>>> x
0
>>> i = 101
>>> x = 2 if i>100 else 1 if i<100 else 0
>>> x
2
>>> i = 99
>>> x = 2 if i>100 else 1 if i<100 else 0
>>> x
1