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I am wondering why the following variable is treated like a number?
a = 1_000_000 print (a) 1000000
Shouldn't print(a) return 1_000_000?
256
Python allows you to put underscores in numbers for convenience. They're used to separate groups of numbers, much like commas do in non-programming. Underscores are completely ignored in numbers, much like comments. So this: x = 1_000_000. is interpreted to be the same as this: x = 1000000.
Underscore(_) is also used to ignore the values. If you don't want to use specific values while unpacking, just assign that value to underscore(_). Ignoring means assigning the values to special variable underscore(_). We're assigning the values to underscore(_) given not using that in future code.
An underscore in front usually indicates an instance variable as opposed to a local variable. It's merely a coding style that can be omitted in favor of "speaking" variable names and small classes that don't do too many things.
Single Trailing Underscore( var_ ): Used by convention to avoid naming conflicts with Python keywords. Double Leading Underscore( __var ): Triggers name mangling when used in a class context. Enforced by the Python interpreter.
With Python 3.6 (and PEP-515) there is a new convenience notation for big numbers introduced which allows you to divide groups of digits in the number literal so that it is easier to read them.
Examples of use:
a = 1_00_00 # you do not need to group digits by 3! b = 0xbad_c0ffee # you can make fun with hex digit notation c = 0b0101_01010101010_0100 # works with binary notation f = 1_000_00.0 print(a,b,c,f) 10000
50159747054
174756
100000.0
print(int('1_000_000')) print(int('0xbad_c0ffee', 16)) print(int('0b0101_01010101010_0100',2)) print(float('1_000_00.0')) 1000000
50159747054
174756
100000.0
A = 1__000 # SyntaxError: invalid token Python allows you to put underscores in numbers for convenience. They're used to separate groups of numbers, much like commas do in non-programming. Underscores are completely ignored in numbers, much like comments. So this:
x = 1_000_000 is interpreted to be the same as this:
x = 1000000 However, you can't put two underscores right next to each other like this:
x = 1__000__000 #SyntaxError If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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