Boolean is a mathematical or logical term used for True and False and related operations. Python also provides boolean types, operators, and operations. Boolean provides two types called True and False. Keep in mind that “True” and “False” are string types that are different.
Bool or Boolean Type
Boolean is a type which can store True
and False
values. The boolean type can not store another value. The boolean type is called as Bool
in Python and the base class is named as bool
and expressed as <class 'bool'>
.
b = True
print(type(b))
<class 'bool'>
c = False
print(type(c))
<class 'bool'>
Keep in mind that the True and False first letter should be uppercase in order to specify the bool value. If the first letter is lowercase you will get the “NameError: name ‘true’ is not defined” error.
>>> b = true
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
NameError: name 'true' is not defined
Boolean True
is a value used to describe truthness or positive value. Generally, other types like integer, floating-point, string, etc can be converted into bool type by using the bool()
method. The bool() method is provided as builtin.
print( bool(1) )
# True
print( bool(-1) )
# True
print( bool(0) )
# False
print( bool(1.1) )
# True
print( bool(-1.1) )
# True
print( bool("") )
# False
print( bool('') )
# False
print( bool("python") )
# True
print( bool([]) )
# False
print( bool([ 1, 2 , 3 ]) )
# True
Boolean Operations
The bool values True and False can be used in different boolean operations. As expected the results of the boolean operation will be a bool value True or False. Python provides the following bool or boolean operations.
- Equal Operation
- Not Equal Operation
- And Operation
- Or Operation
- Not Operation
Boolean Equal
The equal operation will check if the given two values or data are the same and if they are the same returned value will be True. If they are not the same the returned bool value will be False.
print( 1==1 )
# True
print( ""=='' )
# True
print( "ismail"=="ismail" )
# True
print( 1==-1 )
# False
print( 0==-0 )
# True
Boolean Not Equal
The negative form of the boolean operation equal is Not equal
. Not equal operation and operator is expressed as !=
to check two given values. If the values are the same it will return False and if the values are not the same it will return True.
print( 1!=1 )
# False
print( ""!='' )
# False
print( "ismail"!="ismail" )
# False
print( 1!=-1 )
# True
print( 0!=-0 )
# False
Boolean AND Logic
and
logic or operator is used with the calculation of two bool values. and the operator returns a bool value according to the provided parameters. The following table provides all calculation variations about the and operator.
AND Operator | Result |
---|---|
True and False | False |
True and True | True |
False and True | False |
False and False | False |
Boolean OR Logic
or
logic or operator is used with the calculation of two bool values. or
the operator returns a boolean value according to the provided parameters. The following table provides all calculation variations about the and operator.
OR Operator | Result |
---|---|
True or False | True |
True or True | True |
False or True | True |
False or False | False |
Boolean NOT Logic
not
logic or operator is used to return the reverse of the given boolean value. If the boolean value is True not operator will return False. If the boolean value is False the not operator will return True.
print(not False)
# True
print(not True)
# False
print(not True == False)
# True
print(not True == (1 != 1))
# True
Complete Boolean Logic Operator and Operations Table
A | B | not A | not B | A == B | A =! B | A or B | A and B |
---|---|---|---|---|---|---|---|
True | False | False | True | False | True | True | False |
False | True | True | False | False | True | True | False |
True | True | False | False | True | False | True | True |
False | False | True | True | True | False | False | False |