Question

Need help writing these functions in Python:

FUNCTION 1

get_course_ids: Consumes a list of Course dictionaries and returns a list of integers representing course IDs.

Here's what I have so far but I'm getting a Type Error - list indices must be integers or slices, not dict.

def get_course_ids(courses):
course_ids = []

for course in courses:
course_ids.extend(courses[course])
  
return course_ids

FUNCTION 2

choose_course: Consumes a list of integers representing course IDs and prompts the user to enter a valid ID, and then returns an integer representing the user's chosen course ID. If the user does not enter a valid ID, the function repeatedly loops until they type in a valid ID. You will need to use the input function to get the user's choice.

Answer 1

Funtion1 :

def get_course_ids(courses):
   course_ids = []
   for course in courses:
       course_ids.extend(courses[course])
   return course_ids

the above one is your code.

Observe the for loop which is indeed a for each loop.
So inorder to acces each element, it is not necessary to use list name with indexing again.

course_ids.extend(courses[course]) -- this is bug line
replace tha above line with below line

course_ids.extend(course) --- course itself is a single value in the list

the modified function will look like this ---

def get_course_ids(courses):
   course_ids = []
   for course in courses:
       course_ids.extend(course)
   return course_ids

Funtion 2 :

# returns an integer representation of the given course id

# please enter digits as input
# on giving non-digits as input, this program may give error
def choose_course(courses):
   # taking input from user
   cid = int(input("Enter a course ID : "))
   while cid not in courses ;
       # ask input until user enters a valid input
       print("Wrong input")
       cid = int(input("Enter a course ID : "))

   # I'm not sure what is integer representation of the Course ID as Course ID itself is a integer
   # so I'm returning index of the given course ID
   # If you feel this is incorrect you can change and return your required value
   re = courses.index(cid)
   return re