Python - Function and Output (Day 10)

This is a 100 Days challenge to learn a new language (Python). 100 Days of Code - The Complete Python Pro Bootcamp 

I will post some notes to motivate myself to finish this challenge.

Built-in function with input and output

Ex:

# Built-in Function: len()

#   input_string": Input

#   string_length: Output

input_string = "Hello World"

string_length = len(input_string)

Custom function with input and output

Ex:

# Custom Function: format_name()

#   'fRANK' and 'CHENG': Input

#   formatted_string   : Output

# title(): https://www.w3schools.com/python/ref_string_title.asp

def format_name(f_name, l_name):

    """Take first name and last name to format it, and

    return the title case version of the name."""

    formatted_f_name = f_name.title()

    formatted_l_name = l_name.title()

    return f"{formatted_f_name} {formatted_l_name}"

formatted_string = format_name("fRANK", "CHENG")

print(formatted_string)

Docstring

Used to provide more information of the function you created. It starts from """ and ends with """.

Reference

Challenge - Days in Month

Ex:

# determine the input year is leap year or not

def is_leap(year):

    if year % 4 == 0:

        if year % 100 == 0:

            if year % 400 == 0:

                return True

            else:

                return False

        else:

            return True

    else:

        return False

# checking how many days in a provided month

def days_in_month(year, month):

    month_days = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]

    if is_leap(year) and month == 2:

        return 29

    else:

        return month_days[month-1]

year = int(input("Enter a year: "))

month = int(input("Enter a month: "))

days = days_in_month(year, month)

print(days)

Result:

Enter a year: 2022 Enter a month: 2 28

Challenge - Calculator

Ex:

# Add

def add(n_1, n_2):

    return n_1 + n_2

# Sub

def sub(n_1, n_2):

    return n_1 - n_2

# Mul

def mul(n_1, n_2):

    return n_1 * n_2

# Div

def div(n_1, n_2):

    return n_1 / n_2

# Store all operation functions to an dictionary

operations = {

    "+": add,

    "-": sub,

    "*": mul,

    "/": div,

}

def cal():

    # flag

    keep_continue = True

    # Ask for the first number

    num1 = int(input("What's your first number? "))

    # Show operations

    for symbol in operations:

        print(symbol)

    while keep_continue:

        # ask for operator

        operation_symbol = input("Pick an operation: ")

        # Ask for the next number

        num2 = int(input("What's your next number? "))

        answer = operations[operation_symbol](num1, num2)

        print(

            f"{ num1 } {operation_symbol} {num2} =

{operations[operation_symbol](num1, num2)}"

        )

        cal_continue = input(

            f"Type 'y' to continue calculation with { answer }, or

type 'n' to start a new calculation, or type anything

to exit: "

        )

        if cal_continue == "y":

            num1 = answer

        elif cal_continue == "n":

            keep_continue = False

            cal()

        else:

            keep_continue = False

cal()

Result:

What's your first number? 2 + - * / Pick an operation: + What's your next number? 3 2 + 3 = 5 Type 'y' to continue calculation with 5,

or type 'n' to start a new calculation, or type anything to exit: y Pick an operation: * What's your next number? 2 5 * 2 = 10 Type 'y' to continue calculation with 10,

or type 'n' to start a new calculation, or type anything to exit: exit

Why store functions inside a python dictionary?

Reference