webinar-for-loops-2023-11-04

# 2023 Nov 4
# WEBINAR: For Loops

# We use loops to repeat actions

# a WHILE loop... is an IF that repeats as long as the loop condition remains True

# FOR LOOPS are used for repeating actions for every element in a container (list, str, tuples, sets, dictionary, range objects)

# Basic syntax of a for loop
# for ___ in __someContainer__:

# list
myList = ["Agent Scully", "Agent Mulder", "Walter Skinner", "CSM", "Mr. X"]
for item in myList:
    print(item)

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

# string
myString = "It was the best of times."
for char in myString:
    print(char)

for char in myString:
    # if not char.isspace():
    if char.isalpha():
        print(char)

# for key in myDict:
#     # myDict[key]
#     # myDict[key] = value
bestOfXF = {
    "1x00": "Pilot",
    "2x10": "Red Museum",
    "2x14": "Die Hand Die Verletzt",
    "3x04": "Clyde Bruckman's Final Repose",
    "3x12": "War of the Coprophages",
    "3x20": "Jose Chung's From Outer Space",
    "4x05": "The Field Where I Died",
    "5x05": "The Post Modern Prometheus",
    "5x17": "All Souls"
}
for k in bestOfXF:
    # "Check out Episode ___ or '___'"
    print(f"Check out Episode {k} or '{bestOfXF[k]}'")

# membership check... in
print("5x05" in bestOfXF) # True... b/c key is in dict
print("6x01" in bestOfXF) # False
print("All Souls" in bestOfXF) # False... that is not KEY in this dict

# if I wanted to check if something is present as a dict VALUE
# myDict.values() - returns a special container type with just the values
print("All Souls" in bestOfXF.values()) # True

# what is the VALUE for this KEY
# we can get that directly: myDict[key]
print(bestOfXF["5x05"])

# what is the KEY for this VALUE
# loop through dict and check each value, remember the key where found
# say I got "All Souls" from input(), is it a value and what's the key?
for key in bestOfXF:
    if bestOfXF[key] == "All Souls":
        print(key)
# if I make it this far without finding it, I can say it's not there

# range()... a range object, which we use to loop a number of times
# range(0, 5) # [0, 1, 2, 3, 4]
for num in range(5):
    print(num)

# using range() to correspond to index
for i in range(len(myList)):
    # print(myList[i])
    print(f"Position {i} is {myList[i]}")

# or... use enumerate() to get index and value
for i, item in enumerate(myList):
    print(f"Position {i} is {item}")