The if statement evaluates an expression to either True or False.
If the expression evaluates to True, then the code in the if statement will be executed.

Using the equality (=) operators: x = 0 if x == 0: print('zero') else: print('non zero') if x == 0: print('zero') elif x > 0: print('positive') else: print('negative')
Using the inequality (!=) operators: x = 0 if x != 0: print('non zero') else: print('zero')
Using and/or operators: x = 0 y = 0 if x == 0 or y == 0: print('x * y = zero') elif (x > 0) and (y > 0): print('x * y = positive') else: print('x * y = negative')
Checking if a value is in a list: z = [0, 1, 2, 3] x = 0 if x in z: print(f'{x} is in the list {z}') else: print(f'{x} is not in the list {z}')
Checking if a value is not in a list: z = [0, 1, 2, 3] x = 0 if x not in z: print(f'{x} is not in the list {z}') else: print(f'{x} is in the list {z}')
Checking if a list is empty: z = [0, 1, 2, 3] if z: # python return True if the list contains at least one item print(f'{z} is not empty') else: print(f'{z} is empty')