webinar-for-loops-2024-02-02

# # 2024 Feb 03
# # 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, dict, tuple, str)

# 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)

# dict
# myDict = {
#     key: value,
#     key: value,
#     key: value
# }
# myDict[key] # get the value for that key
# myDict[key] = value # assign a value for that key
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 key in bestOfXF:
    # key is key
    # bestOfXF[key] is its value
    # value = bestOfXF[key] # if you like
    # "Check out Episode ___ or '___'"
    print(f"Check out Episode {key} or '{bestOfXF[key]}'")

# looping a known number of times
# RANGE
# range(start=0, stop, step=1)
for num in range(0, 5): # [0, 1, 2, 3, 4]
    print(num)


# Need to know index? Range of length
myList.append("Krycek")
myList.append("Queequeg")
myList.append("Frohicke")
for i in range(0, len(myList)):
    print(f"{i} is {myList[i]}")

# process in pairs
for i in range(0, len(myList), 2):
    print(f"{myList[i]} hates {myList[i+1]}")

# another way to loop focused on the index
for i, item in enumerate(myList):
    print(f"{i} --> {item}")


# Common Pattern
# "fill the basket"

# make a new container from previous one
newList = [] # start with empty new container
for item in myList:
    # filter!
    # if item[0] == "a" or item[0] == "A":
    if item.lower().startswith("a"):
        newList.append(item)
print(newList)