Python supports the usual logical mathematical conditions which can be used in several ways, most commonly in various “if statement” types and loops.

• Equals: a == b
• Not Equals: a != b
• Less than: a < b
• Less than or equal to: a <= b
• Greater than: a > b
• Greater than or equal to: a >= b

Basically, “if” the statement is true, do something.

x = 88
y = 100

if y > x:
    print("y is greater than x")

Shorthand version:

x = 88
y = 100

if y > x: print("y is greater than x")

Output:

y is greater than x

The elif keyword basically says if the previous conditions were not true, then try this condition.

x = 12
y = 12

if y > x:
    print("y is greater than x")
elif x == y:
    print("x and y are equal")

Output:

x and y are equal

The else keyword catches anything which isn’t caught by the preceding conditions.

x = 99
y = 88

if y > x:
    print("y is greater than x")
elif x == y:
    print("x and y are equal")
else:
    print("x is greater than y")

Output:

x is greater than y

The and keyword is a logical operator, and is used to combine conditional statements.

x = 100
y = 88
z = 200

if x > y and y < z:
    print("Both conditions are true")

Output:

Both conditions are true

The or keyword is a logical operator, and is used to combine conditional statements.

x = 100
y = 88
z = 200

if x < y or y < z:
    print("One of the conditions is true")

Output:

One of the conditions is true

The not keyword is a logical operator, and is used to reverse the result of the conditional statement.

x = 8
y = 10

if not x > y:
    print("a is NOT greater than b")

Output:

a is NOT greater than b

if statements cannot be empty, but if you so have an if statement with no content, a pass statement can be placed to avoid getting an error.

x = 5
y = 12

if y > x:
    pass

Output:

#there will be no output, and no error will be thrown

Nesting if statements is when there are if statements inside other if statements.

x = 88

if x > 10:
    print("x is more than 10")
    if x > 50:
      print("and also above 50")
    else:
      print("but not above 50")

Output:

x is more than 10
and also above 50

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