def apply(criteria,n):
    """ criteria is a function that takes in a number and returns a Boolean
        n is an int
    Returns how many ints from 0 to n (inclusive) match the criteria 
    (i.e. return True when criteria is applied to them)
    """ 
    count = 0
    for i in range(0, n+1):
        if criteria(i):
            count += 1
    return count

def is_even(x):
    return x%2==0

def is_5(x):
    return x==5

# print('apply with is_5:',apply(is_5,10))
# print('apply with anon fcn:', apply(lambda x: x==5, 100))


# Shown another way, the following are equivalent:
# is_even(8)              # returns True
# (lambda x: x%2==0)(8)   # returns True


# 1. What does this print?
# print(apply(lambda x: x%2==0, 10))

# 2. Call apply on n=100 and a lambda func 
#    that takes in a parameter and returns 
#    whether the parameter is a multiple of 10
#    What does it print?
# your code here


def do_twice(n, fn):
    return fn(fn(n))

# print(do_twice(3, lambda x: x**2))


###################
### example with returning a tuple with many values
###################
def quotient_and_remainder(x, y):
      q = x // y
      r = x % y
      return (q, r)

# result = quotient_and_remainder(10,3)
# print(result)

# (quot, rem) = quotient_and_remainder(5,2)
# print('quotient is:', quot)
# print('remainder is:', rem)



############### YOU TRY IT #####################
# Write a function that meets these specifications:
def char_counts(s):
    """ s is a string of lowercase chars 
    Returns a tuple where the first value is the 
    number of vowels in s and the second value 
    is the number of consonants in s 
    """
    # your code here


# print(char_counts("abcd"))  # prints (1,3)
# print(char_counts("zcght"))  # prints (0,5)

##################################################


###################
### example of variable number of arguments
###################
def mean(*args):
    """
    Assumes at least one argument and all arguments are numbers. 
    Returns the mean of the arguments.
    """
    tot = 0
    for a in args:
        tot += a
    return tot/len(args)

# print(mean(1,2,3,4,5,6))
# print(mean(6,0,9))

## Compare above code with this one:
# Note args vs *args and mean((6,0,9)) vs mean(6,0,9)
def mean(args):
    tot = 0
    for a in args:
        tot += a
    return tot/len(args)

# print(mean((1,2,3,4,5,6)))
# print(mean((6,0,9)))

##################
## EXAMPLE: sum element values in a list 
##################
def list_sum(L):
    total = 0 
    for e in L: 
        total += e 
    return(total)

# print(list_sum([1,3,5]))


###################
## EXAMPLE: sum lengths of string elements
####################
def len_sum(L):
    total = 0 
    for s in L: 
        total += len(s) 
    return(total)

# print(len_sum(['ab', 'def', 'g']))


#################################################



################## YOU TRY IT ###################
def sum_and_prod(L):
    """ L is a list of numbers 
    Return a tuple where the first value is the 
    sum of all elements in L and the second value 
    is the product of all elements in L 
    """
    # your code here

 

# print(sum_and_prod([4,6,2,5]))   # prints (17, 240)





#############################################
################## ANSWERS TO YOU TRY IT ####################
#############################################
def char_counts(s):
    """ s is a string of lowercase chars 
    Returns a tuple where the first value is the 
    number of vowels in s and the second value 
    is the number of consonants in s 
    """
    vowels, cons = 0, 0
    for i in s:
        if i in "aeiou":
            vowels += 1
        else:
            cons += 1
    return (vowels, cons)

# print(char_counts("abcd"))  # prints (1,3)
# print(char_counts("zcght"))  # prints (0,5)


def sum_and_prod(L):
    """ L is a list of numbers 
    Return a tuple where the first value is the 
    sum of all elements in L and the second value 
    is the product of all elements in L 
    """
    s, p = 0, 1
    
    for i in L:
      s += i
      p *= i
    return (s, p)

# print(sum_and_prod([1,2,3,4]))   # prints (10, 24)
# print(sum_and_prod([12,6,2,7]))   # prints (27, 1008)


#############################################
################## AT HOME ####################
#############################################

# Trace this code:
# Figure out what it returns and then run it to check yourself.
def always_sunny(t1, t2):
    """ t1, t2 are non-empty """
    sun = ("sunny", "sun")
    first = t1[0] + t2[0]
    return (sun[0], first)

# always_sunny(('cloudy' ), ('cold',))  # returns what?



def max_of_both(n, f1, f2):
    """ n is an int
        f1 and f2 are functions that take in an int and return a float
    Applies f1 and f2 on all numbers between 0 and n (inclusive). 
    Returns the maximum value of all these results.
    """
    # your code here

# print(max_of_both(2, lambda x:x-1, lambda x:x+1))  # prints 3
# print(max_of_both(10, lambda x:x*2, lambda x:x/2))  # prints 20


def sublist_sum(L):
    """ L is a list whose elements are lists with int elements
    Returns the sum of all int elements. """
    # your code here

# print(sublist_sum([[1,2], [4,5,6]])) # prints 18


#############################################
################## ANSWERS TO AT HOME ####################
#############################################

def max_of_both(n, f1, f2):
    """ n is an int
        f1 and f2 are functions that take in an int and return a float
    Applies f1 and f2 on all numbers between 0 and n (inclusive). 
    Returns the maximum value of all these results.
    """
    # your code here
    maxval = f1(0)
    for i in range(n+1):
        if f1(i) > maxval:
            maxval = f1(i)
        if f2(i) > maxval:
            maxval = f2(i)
    return maxval

# print(max_of_both(2, lambda x:x-1, lambda x:x+1))  # prints 3
# print(max_of_both(10, lambda x:x*2, lambda x:x/2))  # prints 20


def sublist_sum(L):
    """ L is a list whose elements are lists with int elements
    Returns the sum of all int elements. """
    ## One way by using the sum function over the sublist
    tot = 0
    for subL in L:
        tot += sum(subL)
    return tot
    ## Alternate way by nesting a for loop that 
    ## iterates over the sublist's int elements
    tot = 0
    for subL in L:
        for e in subL:
            tot += e
    return tot
    

# print(sublist_sum([[1,2], [4,5,6]])) # prints 18