# Write a function that takes a list of numbers as a parameter, and
# returns the sum of the list.


def listsum1(mylist):
    thesum = 0
    for i in range(len(mylist)):
        thesum += mylist[i]
    return thesum

print listsum1([1, 2, 3])
print listsum1([-1, -2, -3])
print listsum1([3, -3])
print listsum1(4 * [0])
print listsum1([])




def listsum2(mylist):
    thesum = 0
    for val in mylist:
        thesum += val
    return thesum


print listsum2([1, 2, 3])
print listsum2([-1, -2, -3])
print listsum2([3, -3])
print listsum2(4 * [0])
print listsum2([])

def listsum3(mylist):
    #there's a built-in sum function!
    #you won't be allowed to use in exam 2 most probably
    return sum(mylist)

print listsum3([1, 2, 3])
print listsum3([-1, -2, -3])
print listsum3([3, -3])
print listsum3(4 * [0])
print listsum3([])


# Write a function that takes two parameters:
# - a list of strings and
# - an integer minlen.
# The function should return a count of all the
# strings in the list that are longer than minlen.


def stringCount(mylist, minlen):
    '''(list, int) -> int
    Return a count of the number of strings
    inmylist longer than minlen.
    '''
    count = 0
    for str in mylist:
        if len(str) > minlen:
            count += 1
    return count

# Write another version of this function that returns
# a list of all the strings that are longer than minlen


def stringFilter(mylist, minlen):
    '''(list, int) -> list
    Return a list with all strings from
    mylist longer than minlen.
    '''
    newlist = []
    for s in mylist:
        if len(s) > minlen:
            newlist += [ s ]
    return newlist


#Write a function that takes an integer N as a parameter and
#constructs and returns a list of positive integers from
#1 to N that evenly divide into that number.
#For example if N is 4, the function should return [1,2,4].

def getDivisors(N):
    '''Return a list of divisors of the positive integer N.'''
    divisors = []
    for i in range(1,N+1):
        if N % i == 0:
            divisors = divisors + [i]
    return divisors

#Write a function that takes a list of integers representing
#daily temperatures. Compute and return a list that contains
#the [minimum, average, maximum] values.


def daily_temperatures(temperature_list):
    '''''Compute the min, average, and max of a list of daily temps.
    Return a list of 3 items: min, average, and max.'''
    
    min_value = min(temperature_list)
    max_value = max(temperature_list)
    average = sum(temperature_list) / float(len(temperature_list))
    return [min_value, average, max_value]