webinar-for-loops-2022-06-22

# 2022 June 11
# WEBINAR: For Loops
# We use loops to repeat actions

# a WHILE loop... btw.. 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 syntax of a for loop
# for ___ in __someContainer__:
myList = ["Agent Scully", "Agent Mulder", "Walter Skinner", "CSM", "Mr. X"]
for item in myList:
    print(item)

# if you ever override the end param of print() btw...
for item in myList:
    print(item, end=" ")
print() # start a clean line afterward

myTuple = ("Gilligan", "Castaway002", "red", "crew")
for item in myTuple:
    print(item)

scoobiesDCT = {
    "Scooby": "a blue collar",
    "Shaggy": "green",
    "Velma": "orange",
    "Daphne": "purple",
    "Fred": "an ascot"
}
for key in scoobiesDCT: # loop var holds the key, regardless of the name
    # myDictionary[key] # retrieve the value for that key
    # myDictionary[key] = new value for that key
    value = scoobiesDCT[key]
    print("{} wears {}.".format(key, value))


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

myString = "In a hole in the ground there lived a Hobbit..."
for char in myString:
    print(char, end="-")
print()

print(dir(str))
# know your WHITESPACE
# " " # the space you get from the spacebar
"\n"
"\t"
"\r"
"\b"
"\f"
"\v"
# ... and then there's ~20 Unicode variations on a space

# just looping some number of times
for n in range(5): # sorta like [0, 1, 2, 3, 4]
    print(n)

for i in range(len(myList)):
    print("{}: {}".format(i, myList[i]))


# student questions
print(", ".join(myList))
print(", ".join(myTuple))

numList = [1, 2, 3, 4]
numStrList = []
for num in numList:
    numStrList.append(str(num))
print(numStrList) # ['1', '2', '3', '4']
# print(", ".join(numList)) # error! Must be a container of strings, not integers!
print(", ".join([str(num) for num in numList]))

numList = [5, 6, 7, 8]
for i in range(len(numList)):
    numList[i] = str(numList[i])
print(numList) # ['5', '6', '7', '8']
numTuple = tuple(numList)
print(numTuple) # ('5', '6', '7', '8')