Single Underscore
Example 1: Single Underscore In Interpreter:
_ returns the value of the last executed expression value in Python Prompt/Interpreter
Example 2: Single Underscore for ignoring values
Multiple times we do not want return values at that time to assign those values to Underscore. It is used as a throw-away variable.
Python3
# Ignore a value of specific location/index for _ in range ( 10 ) print ( "Test" ) # Ignore a value when unpacking a,b,_,_ = my_method(var1) |
Example 3: Single Underscore after a name
Python has theirs by default keywords which we can not use as the variable name. To avoid such conflict between python keyword and variable we use underscore after the name
Python3
class MyClass(): def __init__( self ): print ( "OWK" ) def my_definition(var1 = 1 , class_ = MyClass): print (var1) print ( class_ ) my_definition() |
Output:
1 <class '__main__.MyClass'>
Example 4: Single Underscore before a name
Leading Underscore before variable/function /method name indicates to the programmer that It is for internal use only, that can be modified whenever the class wants. Here name prefix by an underscore is treated as non-public. If specify from Import * all the names starting with _ will not import. Python does not specify truly private so this one can be called directly from other modules if it is specified in __all__, We also call it weak Private
Python3
class Prefix: def __init__( self ): self .public = 10 self ._private = 12 test = Prefix() print (test.public) print (test._private) |
10 12
Example 5: Single underscore in numeric literals
The Python syntax is utilized such that underscores can be used as visual separators for digit grouping reasons to boost readability. This is a typical feature of most current languages and can aid in the readability of long literals, or literals whose value should clearly separated into portions.
Python3
# grouping decimal for easy readability of long literals amount = 10_000_000 . 0 # grouping hexadecimal for easy readability of long literals addr = 0xCAFE_F00D # grouping bits for easy readability of long literals flags = 0b_0011_1111_0100_1110 |
Underscore (_) in Python
In this article, we are going to see Underscore (_) in Python.
Following are different places where “_” is used in Python:
- Single Underscore:
- Single Underscore in Interpreter
- Single Underscore after a name
- Single Underscore before a name
- Single underscore in numeric literals
- Double Underscore:
- Double underscore before a name
- Double underscore before and after a name