Lệnh if

number = 15
conclusion = ''

if number < 0:
    conclusion = 'Number is less than zero'
elif number == 0:
    conclusion = 'Number equals to zero'
elif number < 1:
    conclusion = 'Number is greater than zero but less than one'
else:
    conclusion = 'Number bigger than or equal to one'

assert conclusion == 'Number bigger than or equal to one'