webinar-python-functions-methods-2022-04-16

# Webinar: Functions + Methods in Python

# You'll start getting to know functions in Ch 7

# A function is essentially a block of code with a name
# that can (or not) accepts inputs as arguments and perform
# some actions accordingly.

# Functions should be modular and reusable - a good function has ONE JOB
# We define a function once and call it as many times as needed

# def myFunction(parameter): # calls provide values into parameter variables
#     # so don't do this:
#     # parameter = 5 # No! We don't assign values to parameters this way
#     newValue = parameter/2 # whatever the function is doing
#     return newValue # return vs print, do one not both
#     print(newValue) # this would not execute, since we already returned

def returnATuple(x, y, z): # x, y, z are parameters
    return z, y, x # same as return (z, y, x)
x = returnATuple(1, 2, 3) # 1, 2, and 3 are ARGUMENTS going into each parameter
print("{}: {}".format(x, type(x)))

# function definition, Gallant
def squareThis(num):
    return num * num
print(squareThis(3)) # 9? yes
print(squareThis(5)) # 25? yes

# function definition, Goofus
def squareSomething(num):
    num = 5 # no, Goofus! Don't override your parameter!
    return num * num
print(squareSomething(3)) # Goofus hopes you like 25
print(squareSomething(6)) # on every...
print(squareSomething(9)) # single call :(

# Examples and Student Questions

# Ch 8 Task 1
# Complete the function to print the first X
# number of characters in the given string
def printFirst(mystring, x):
    # pass
    print(mystring[0:x])

# expected output: WGU
printFirst('WGU College of IT', 3)
# expected output: WGU College
printFirst('WGU College of IT', 11)
printFirst("WKRP in Cincinnati", 4) # add a test call of your own


# if name = main, a structure you'll see first Lab 7.18
# this structure helps us separate different testing of our code


# define your function outside of the IF
# just the function definition

# the IF block below only executes when this very file is run
# (and NOT if this file is imported into another py file)

# if __name__ = "__main__":
    # grab data with input()
    # call your function
    # anything else to finish up

# Seen in 7.18:

# And another good example 7.22
# Define your function here.
def swap_values(user_val1, user_val2):
    return user_val2, user_val1 # that's a tuple, whether we wrapped in () or not

if __name__ == '__main__':
    # Type your code here. Your code must call the function.
    int1 = int(input())
    int2 = int(input())
    myTuple = swap_values(int1, int2)
    print("{} {}".format(myTuple[0], myTuple[1]))

# Student question (no writing your own function on this one, but..)
# Lab 8.9
# In Ch 8 you'll start really getting to know your string METHODS
userInput = input()
noSpaces = ""

for char in userInput:
    if char.isalpha(): # class methods are functions too!
        noSpaces += char
print(noSpaces) # just like the built-in functions!

# Remember that the built-in functions and class methods like str.strip() and list.append()
# are functions just like the functions you write. They all follow the same rules.