Python, why elif keyword?

Question

Hi!

I just started python programming!
There's one thing I wondered about, the "elif" keyword.

Any other programming languages I used before use simply the "else if" syntax.
Does anyone have an idea why the python developers add the additional "elif" keyword?

Why not:

if a:
    print("a")
else if b:
    print("b")
else:
    print("c")

Answer 1

Most likely its syntactic sugar. Like the Wend of Visual Basic.

Answer 2

Far as I know, it's there to avoid excessive indentation. You could write

if x < 0:
    print 'Negative'
else:
    if x == 0:
        print 'Zero'
    else:
        print 'Positive'

but

if x < 0:
    print 'Negative'
elif x == 0:
    print 'Zero'
else:
    print 'Positive'

is just so much nicer.

Answer 3

Python inherits this from Perl, where it's called elsif.

In Python's case, else if as two separate constructs like it is in C-like languages would be quite ugly as you'd have to have else: if: with two indenting levels.

It's arguable whether special-casing the two keywords together would be better (so making else if a single construct, like the not in operator.

PL/SQL also has elsif, and the C preprocessor has it spelled elif.

Answer 4

To avoid brace^H^H^H^H^Helse if war.

In C/C++ where you have an else if, you can structure your code in many different styles:

if (...) {
    ...
} else if (...) {
    ...
}


if (...) {
    ...
} 
else if (...) {
    ...
}

if (...) {
    ...
} else 
if (...) {
    ...
}

// and so on

by having an elif instead, such war would never happen since there is only one way to write an elif. And also, elif is much shorter than else if.

Answer 5

That's just the way it is. Javascript uses else if, php uses elseif, perl uses elsif, the C preprocessor and python use elif. None of them are wrong, they just choose slightly different syntax to do the same thing. :D

Answer 6

elif is some sort of replacement for switch in other languages but with more power

for example in C you write

switch (number){
 case 1:
   doA()
   break;
 case 2:
   doB()
   break;
 case N:
   doN()
   break;
 default:
   doSomethingElse()
   break;
}

in Python you write

if number == 1: doA()
elif number == 2: doB()
elif number == N: doC()
else: doSomethingElse()

As you see elif is more powerful since you can put more complex statements than in a switch, plus avoid nesting if/else statements

Answer 7

else if in python called elif

if a:
    print "a" 
elif b:
    print "b" 
else:
    print "c"