webinar-for-loops-2022-04-09

# 2022 Apr 9
# 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)

myTuple = ("Gilligan", "Castaway002", "red", "crew") # return x, y
for item in myTuple:
    print(item) # print(end="\n")

myString = "Just sit right back and you'll hear a tale."
for char in myString:
    print(char, end="-")
print() # if you use end param of print(), print() again to get a clean line

# looping over dictionaries
scoobiesDCT = { # key: value pairs
    "Scooby": "a blue collar",
    "Shaggy": "green",
    "Velma": "orange",
    "Daphne": "purple",
    "Fred": "an ascot"
}
# you can use the dict KEY to get its VALUE
# myDictionary[key] # retrieve the value for that key... kinda like dict.get()
# myDictionary[key] = value # set a new value, kinda like dict.update()

for key in scoobiesDCT: # for loop var with dicts is the KEY
    value = scoobiesDCT[key]
    print("{} wears {}.".format(key, value))

# loop some number of times... with range()
# for n in 5: # can't do that! 5 is not iterable.
for n in range(0, 5):
    print(n)

# using range() to look at index of list items
myList.append("Krycek")
for i in range(len(myList)):
    print("{}: {}".format(i, myList[i]))
for i, item in enumerate(myList):
    print("{}--> {}".format(i, item))

# CA 6.8.2
# Given num_rows and num_cols, print a list of all seats in a theater. Rows are numbered, columns lettered, as in 1A or 3E. Print a space after each seat.
# Sample output with inputs: 2 3
# 1A 1B 1C 2A 2B 2C

num_rows = 2 # int(input())
num_cols = 3 # int(input())

# x += 1
# string incrementing
# ord("a") + 1
# chr(ord("a") + 1) # --< "b"

for row in range(1, num_rows+1):
    ltr = "A"
    for col in range(0, num_cols):
     print("{}{}".format(row, ltr), end=" ")
     ltr = chr(ord(ltr) + 1)
print()

for i in range(0, 513):
    print("{}: {}".format(i, chr(i)))

with open("mock_data.csv", "r") as f:
    # read() --> returns whole file as one big str
    # readlines() --> returns you a line by line list of strings
    contents = f.readlines()
# print(contents)
for line in contents:
    line = line.rstrip()
    # print(line)
    lineList = line.split(",")
    # print(lineList[3])
    print("{} is coming from: {}".format(lineList[3], lineList[4]))