#!/usr/bin/python3
# -*- coding: utf-8 -*-

# %% Logic

# Boolean values are special primitives
# Note: the capitalization
True
False

# They can be printed:
print(True)
print(False)

# They're objects that can be "stored" in variables too.
varwithtrue: bool = True
varwithfalse: bool = False

# Logical operators

# 'not' flips boolean values
"""
not
Logical NOT operator
Used to reverse the logical state of its operand.
Not(a and b) is True.
"""
print(not True)  # => False
print(not False)  # => True

# Boolean Operators
# Note "and" and "or" are case-sensitive
"""
and
Logical AND operator
If both the operands are true then condition becomes true.
(a and b) is False.
"""
print(True and False)  # => False

"""
or
Logical OR operator
If any of the two operands are non-zero then condition becomes true.
(a or b) is True.
"""
print(False or True)  # => True

# True and False are actually 1 and 0 but with different keywords
print(True + True)  # => 2
print(True * 8)  # => 8
print(False - 5)  # => -5

# Comparison operators look at the numerical value of True and False
print(0 == False)  # => True
print(1 == True)  # => True
print(2 == True)  # => False
print(-5 != False)  # => True

# Use 'is' instead for booleans
print(0 is False)  # => True
print(1 is True)  # => True
print(2 is True)  # => False
print(-5 is not False)  # => True

# Using boolean logical operators on ints,
# casts them (turns them into) to booleans for evaluation,
# but their non-cast value is returned
# Don't mix up with bool(ints) and bitwise and/or (&, |)
print(bool(0))  # => False
print(bool(4))  # => True
print(bool(-6))  # => True
print(0 and 2)  # => 0
print(-5 or 0)  # => -5

# Equality is tested with ==
"""
==
If the values of two operands are equal,
then the condition becomes true.
(a == b) is not true.
"""
print(1 == 1)  # => True
print(2 == 1)  # => False

# Inequality is tested with !=
"""
!=
If values of two operands are not equal,
then condition becomes true.
(a != b) is true.
"""
print(1 != 1)  # => False
print(2 != 1)  # => True

# More comparisons
"""
<
If the value of left operand is less than the value of right operand,
then condition becomes true.
(a < b) is true.
"""
print(1 < 10)  # => True

"""
>
If the value of left operand is greater than the value of right operand,
then condition becomes true.
(a > b) is not true.
"""
print(1 > 10)  # => False

"""
<=
If the value of left operand is less than or equal to
the value of right operand,
then condition becomes true.
(a <= b) is true.
"""
print(2 <= 2)  # => True

"""
>=
If the value of left operand is greater than or equal to
the value of right operand,
then condition becomes true.
(a >= b) is not true.
"""
print(2 >= 2)  # => True

# Determine whether a value is in a range
print(1 < 2 and 2 < 3)  # => True
print(2 < 3 and 3 < 2)  # => False

# Chaining makes this look nicer, in order of number line for ease:
print(1 < 2 < 3)  # => True
print(2 < 3 < 2)  # => False

# These are most understandable when in correct order (above), not like below:
print(3 > 2 > 1)
# Don't do that, numberlines go forward.

# None is a special object in python3
None  # => None
mynone = None
print(mynone)

# Don't use the equality "==" symbol to compare objects to None
# Use "is" instead. This checks for equality of object identity.
print("etc" is None)  # => False
print(None is None)  # => True
print(0 is None)  # => False