#list_ints.py
#demo list of ints

scores = []   #is empty, i.e. no elements, length is 0
n = eval(input("Enter the number of scores you have: "))
for i in range(n):
    num = eval(input("Enter a score: "))
    scores.append(num)

#display as a list     [v1,v2,...,vn]
print(scores)
print(type(scores))
print("Length of scores list:", len(scores))

#access each element using in operator.  "traverse" the list
for scor in scores:
    print(scor, end=" ")
print()

#use index to access each element
for i in range(len(scores)):
    print(i, ":", scores[i])

# scores[i]  # i must be between 0 and len(scores)-1, inclusive, else IndexError crash.

#scores[4] = "asdf"

print("Sum=",sum(scores))   #all elements must be numbers
print("Count=",len(scores))
print("Max=",max(scores))   #all elements must be same type
print("Min=",min(scores))   #  "
print("Average=",sum(scores)/len(scores))
print("Range=",max(scores)-min(scores))

#(repeatedly) search a list. There is no .find() method!
item = eval(input("Enter number to search for in the array: (-999 to quit) "))

while item != -999:
    if item in scores:    
        print("Found it (first) at index:", scores.index(item))  #index: must exist!
        print("#times in the list:", scores.count(item))   #count: 0 OK
    else:
        print("not found")
        print("#times in the list:", scores.count(item))   #count: 0 OK
        
    item = eval(input("Enter number to search for in the array:  (-999 to quit) "))

#reverse the list (does not sort)
scores.reverse()
print(scores)

#sort the list.  Type of elements must be same.
scores.sort()
print(scores)

#inserting
scores.insert(index,value)

#Deleting elements:
# pop() deletes and returns the last element
lastone = scores.pop()
print(lastone)
#list is one shorter
print(scores, " Length:", len(scores))

# pop(index) deletes and returns the index_th element. Any element.
del_i = int(input("Enter the index of the element to remove from the list: "))
removed = scores.pop(del_i)
print(removed)
print(scores, " Length:", len(scores))

# delete an element with the del keyword
#del scores[i]

# delete a known existing value. Error if doesn't exist in the list
#scores.remove(92)


# copy.   3 ways
new_list = scores.copy()
new_list = list(scores)
new_list = scores[:]

#do something to each element, e.g. divide each score by 2
for i in range(len(scores)):
    scores[i] = scores[i] // 2
    print(i, ":", scores[i])
print(scores)