notes to myself (in case I move away from python and come back after a long while) and for beginners

control_flow_1.py

# Might not seem like a big deal in the example but in 
# big projects where there's a lot of control flows branching out
# into unmanageable mess, this will be useful.
# Biggest takeaway is, try to terminate/break/eliminate an edge case in a block and 
# continue the expected control flow in the same indentation level (previous block)


a = {
    'name': 'John Doe',
    'age': '33',
    'location': None,
    'approved': False
}
b = {
    'name': 'Jesper Kyd',
    'age': None,
    'location': 'Kochi',
    'approved': False
}
c = {
    'name': 'Darcy',
    'age': 25,
    'location': 'Venice',
    'approved': False
}

# construct list using above variables and iterate them
for person in [a, b, c]:

    # using walrus operator to assign and eval at the same time
    if not (age := person.get('age')):
        print(f"skipping {person['name']} (no age)")
        # control breaks here
        continue

    # re-assign and eval at the same time using walrus
    if (age := int(age)) > 30:
        tail = "rejected"
        person['approved'] = False
    else:
        tail = "approved"
        person['approved'] = True
    # tail variable is assigned based on approval status
    # the rest of the string concat is the same for rejected
    # or approved. So that logic only needs to be in once place
    print(f"Person {person['name']} ({age}) {tail}")
    # since age is casted to int now, it can be used for math
    print(f"Year of birth is {2022 - age}\n")

how_not_to.py

a = {
    'name': 'John Doe',
    'age': '33',
    'location': None,
    'approved': False
}
b = {
    'name': 'Jesper Kyd',
    'age': None,
    'location': 'Kochi',
    'approved': False
}
c = {
    'name': 'Darcy',
    'age': 25,
    'location': 'Venice',
    'approved': False
}

for person in [a, b, c]:

    age = person.get('age')
    if not age:
        print(f"skipping {person['name']} (no age)")
    else:
        age = int(age)
        if age > 30:
            person['approved'] = False
            print(f"Person {person['name']} ({age}) approved")
        else:
            person['approved'] = True
            print(f"Person {person['name']} ({age}) rejected")
        print(f"Year of birth is {2022 - age}\n")