webinar-for-loops-functions-2021-07-17

# WEBINAR: for loops --- We're almost there... starting in just a moment
# we threw in a Two Fer today and looked at FUNCTIONS + METHODS too

# We use loops to repeat actions
# a WHILE loop is basically an IF statement
# that repeats as long as its condition is true


# FOR LOOPS are used for repeating actions for every element
# in a container like a list, string, tuple, etc...

# BASIC FOR LOOP syntax with a list
myList = ["Agent Scully", "Agent Mulder", "Walter Skinner", "CSM", "Mr. X"] # X-Files characters
myTuple = ("Gilligan", "Castaway002", "red", "crew") # things about Gilligan

# for __ in __:
for item in myList: # I use "item" as my var name with lists, sets, and tuples
    print(item)

for item in myTuple:
    print(item)

myString = "Just sit right back and you'll hear a tale."
for char in myString:
    print(char, end=" ")

# dictionary
# myDCT{
#     key: value,
#     key1: value1
# }
scoobiesDCT = {
    "Scooby": "a blue collar",
    "Shaggy": "green",
    "Velma": "orange",
    "Daphne": "purple",
    "Fred": "an ascot"
}
# for __ in __someDictionary__: # one var?
print() # clear out that extra " " from the last loop
for key in scoobiesDCT:
    # someDictionary[key] --> get the value for that key
    # val = scoobiesDCT[key]
    print("{} always wears {}.".format(key, scoobiesDCT[key]))
    # print("{} always wears {}.".format(key, val))

for k, v in scoobiesDCT.items():
    print("{} almost always wears {}.".format(k, v))

# R A N G E
# range() function creates an iterable sequence from a number or numbers
for n in range(0, 5):
    print(n)

# for item in myList
for i in range(len(myList)):
    print(i, myList[i])

# see also the enumerate() function
for i, item in enumerate(myList):
    print("{} --> {}".format(i, item))

# how many numbers b/n 1 and 100 are div by 25?
count = 0
for n in range(1, 101):
    if n % 25 == 0:
        count += 1
print("How many were divisible?", count)

# how many numbers b/n 32 and 45687987 are div by 77? # I commented this out b/c it takes a long time to run!
# same question as above really
# count = 0
# for n in range(32, 45687987+1):
#     if n % 77 == 0:
#         count += 1
# print("How many were divisible?", count)

# Functions
# Complete the function to PRINT all of the words in the given string
def printWords(mystring):
    # x = 5 # don't do this to parameters
    print(mystring.split()) # correct for this question
    # return mystring.split() # would be wrong here, but would allow us to loop over the returned list


printWords('WGU College of IT')# expected output: ['WGU', 'College', 'of', 'IT']
printWords('Night Owls Rock')  # expected output: ['Night', 'Owls', 'Rock']
printWords('WKRP in Cincinatti') # ['WKRP', 'in', 'Cincinatti']

# function definition, Gallant
def squareThis(num):
    return num * num

print(squareThis(5)) # 25
print(squareThis(9)) # 91

# bad function from Goofus
def squareSomething(num):
    num = 5 # don't do this!
    return num * num

print(squareSomething(5))
print(squareSomething(9))
print(squareSomething(4))

print(1 + squareThis(8)) # 65, we can do this because the function RETURNS or EVALUATES TO an integer value


# METHODS are functions that belong to a class or type, like list.append() or string.replace()
# You'll spend a lot of the later chapters getting to know methods of the common types

# I've modified this so we can leave the printWords() function above alone...
for item in "Come and knock on our door".split(): # the str split() method returns a list, so I can use it like a list
    print(item)

for item in "WKRP in Cincinatti".split():
    print(item)

print(dir(dict)) # dir() returns a list...

for item in dir(list): # ... so I can use it like a list
    if not item.startswith("_"):
        print(item)