Lists and for-loops

lists.py

# sum
def sum(lst):
    """[Number] -> Number
    Returns the sum of all elements of the list
    """
    result = 0
    for el in lst:
        result = result + el
    return result

print(sum([1, 2, 3, 4, 5, 8]))
print("---")


# join
def join(lst):
    """[String] -> String

    Concatenates all the elements of the list
    into a single string
    """
    result = ""
    for el in lst:
        result = result + el
    return result

print(join(["abc", "wxyz", "def"])) # "abcwxyzdef"
print("---")

# reverse

def reverse(lst):
    """[a] -> [a]

    Returns a list that is a reverse of lst
    """
    result = []
    for el in lst:
        result = [el] + result
    return result

print(reverse([1, 2, 3, 4, 5])) # [5, 4, 3, 2, 1]
print(reverse(["abc", "wxyz", "def"])) # ["def", "wxyz", "abc"]

# min

def min(lst):
    smallest = lst[0]
    for el in lst:
        if (el < smallest):
            smallest = el
    return smallest

print(min([5, 3, 2, 8, 7]))


def display_lengths(lst):
    for el in lst:
        print(len(el))

display_lengths(["abc", "wxyz", "def"])


def display(lst):
    for el in lst:
        print(el)

display([1, 2, 3, 4, 5])
display(["abc", "wxyz", "def"])