++ operator in python

If you are one of the guys who are used to programming in c/c++ , one commonly ++ operator in loops.Recently i have been taking a look at python because its one of the most common scripting language around with loads of interesting library/bindings.

So i started writing the usual code for reading a file and counting the number of lines as below

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fh = open("words.txt")
count = 0
for line in fh:
    ++count
    
print "count %d" %count

And running the program i got the following output

	count 0

I was suprised to see the output as there is nothing that can go wrong.OH!! God how naive of me.On turing to my most trused source, Google ofcourse i found the reason as follows [1]

Simple increment and decrement aren’t needed as much as in other languages. You don’t write things like for(int i = 0; i < 10; ++i) in Python very often; instead you do things like for i in range(0, 10).

This make sense because we hard make loops as above in python.

Now that we undestand the reason for such a decision,lets explore a little more.

Why did the interpretor did not throw any error ?

The reason is simple because the + operator is evaluated as unary operator.From the doc of the python

The unary + (plus) operator yields its numeric argument unchanged.

So in the above case the python interprator evalutes to two unary + evaluation and hence the value of the count remains unchanged.

If we try to convert the above code into post increment operator (i.e. count++) the interpretor throws an error as below.

>>> count = 1
>>> count++
  File "<stdin>", line 1
    count++
          ^
SyntaxError: invalid syntax

The above error is thrown as unary operator(+) does not have any operand.

[1] stack overflow answer