Python - Calculate tax (FB - LearnPython.org)

#
# https://www.facebook.com/groups/learnpython.org/permalink/1181939875203961/
#

def calculate_tax(people):

    for key, earning in people.items():

        if earning <= 1000:
            total_tax = 0
        elif earning <= 10000:
            tax1 = 0 #* 1000
            tax2 = 0.1 * (earning - 1000)
            total_tax = tax1 + tax2
        elif earning <= 20200:
            tax1 = 0 #* 1000
            tax2 = 0.1 *9000
            tax3 = 0.15 * (earning - 10000)
            total_tax = tax1+tax2+tax3
        elif earning <= 30750:
            tax1 = 0 #* 1000
            tax2 = 0.1 * 9000
            tax3 = 0.15 * 10200
            tax4 = 0.20 * (earning - 20200)
            total_tax = tax1+tax2+tax3+tax4
        elif earning <= 50000:
            tax1 = 0 #* 1000
            tax2 = 0.1 * 9000
            tax3 = 0.15 * 10200
            tax4 = 0.20 * 10550
            tax5 = 0.25 * (earning - 30750)
            total_tax = tax1+tax2+tax3+tax4+tax5
        else:
            tax1 = 0 #* 1000
            tax2 = 0.1 * 9000
            tax3 = 0.15 * 10200
            tax4 = 0.20 * 10550
            tax5 = 0.25 * 19250
            tax6 = 0.3 * (earning - 50000)
            total_tax = tax1+tax2+tax3+tax4+tax5+tax6

        people[key] = total_tax

    return people

data = {
    'Alex': 500,
    'James': 20500,
    'Kinuthia': 70000
}

calculate_tax(data)
print(data)

# ---

expected_result = {'James': 2490.0, 'Kinuthia': 15352.5, 'Alex': 0}

assert data == expected, "Different results"