Math

1. Arithmetic Operators

Arithmetic operators are used to perform mathematical operations like addition, subtraction, multiplication, division, and more.

• Addition +: Adds two operands together.
• Subtraction -: Subtracts the second operand from the first.
• Multiplication *: Multiplies two operands.
• Division /: Divides the first operand by the second. The result is always a float.

The order of operations in Python is the same as in mathematics. The acronym PEMDAS can help you remember the order:

1. Parentheses
2. Exponents
3. Multiplication and Division (from left to right)
4. Addition and Subtraction (from left to right)

x, y = 3, 6

print(x + y) # Output: 9
print(x - y) # Output: -3
print(x * y) # Output: 18
print(x / y) # Output: 0.5

• If we divide y by x, the result will be 2.0 and not 2. This is because the result of division is always a float in Python.
• For the other arithmetic operators, the result will be an integer if both operands are integers. If one of the operands is a float, the result will be a float.

2. Other Operators

• Floor Division //: Divides the first operand by the second and rounds down the result to an integer.
• Modulus %: Returns the remainder of the division of the first operand by the second.
• Exponentiation **: Raises the first operand to the power of the second operand.

The order of operations for these operators is as follows:

1. Exponentiation **
2. Floor Division // and Modulus %

Example:

x, y = 7, 2

print(x // y) # Output: 3  (7 divided by 2 is 3.5, after rounding down we get 3)
print(x % y)  # Output: 1  (7 divided by 2 is 3, with a remainder of 1)
print(x ** y) # Output: 49 (7 raised to the power of 2 is 49, 7*7 = 49)

3. Shorthand Operators

Python has shorthand operators that allow you to perform the same operation in a more concise way. These are called in-place operators.

Example:

number = 0
number += 5
print(number) # Output: 5

number -=2
print(number) # Output: 3

number +=number
print(number) # Ouput: 6

• += is shorthand for count = count +
• -= is shorthand for count = count -
• *= is shorthand for count = count *
• /= is shorthand for count = count /
• %= is shorthand for count = count %
• //= is shorthand for count = count //
• **= is shorthand for count = count **

4. Logical Operators

1. or

The or operation returns True if at least one of the operands is True. This holds even if we have more than two operands:

a, b, c = False, False, True
print(a or b or c)  # Output: True

2. and

 The and operation returns True if both of the operands is True. This also holds if we have more than two operands:

a, b, c = True, True, True
print(a and b and c)  # Output: True

3. not

The not operation inverts the value of the operand. If the operand is True, the result is False. If the operand is False, the result is True.

a = True
b = False
print(not a)  # Output: False
print(not b)  # Output: True

We can also use the operators in combination. For example, we can negate the result of an AND operation:

a, b = True, False
print(not (a and b))  # Output: True