''' Purpose: consider how to solve questions from Test 3 Fall 2019
'''


# We will provide files for the modules
# for you to write the functions in.
''' TRUTH.PY '''
def dare(): # no parameters
    ''' Returns the logical value True'''
    # return 'True' # not the logical value!
    return True

''' EVAL.PY '''
def eval( n1, c, n2 ): # 3 parameters
# Check what string we pass in for c
# ('+', '-', '*') and return the result
# of the right operation

    if ( c == '+' ):
        result = n1 + n2
    elif ( c == '-' ):
        result = n1 - n2
    elif ( c == '*' ):
        result = n1 * n2
    else:
        result = None
    return result

''' GROW.PY '''
def up( s ): # "single string parameter s"
    result = '' # build up our string
    for ch in s:
        # Add each character twice to the result
        result = result + ch + ch
    return result # return string answer

''' CASE.PY'''
def swap( s ): # single string parameter s
    ''' Returns s but all the characters
    are opposite case'''
    # Accumulator
    result = '' # We are building up a string
    for ch in s: # Look at each character in s
        if ( ch == ch.lower() ):
            # ch is lowercase
            result = result + ch.upper()
            # Add the uppercase version of ch
        else:
            # ch is uppercase
            result = result + ch.lower()
            # Add the lowercase version of ch
    return result

''' STRAY.PY '''
def conv( s ): # single string parameter s
    result = [] # We are building up a list
    for ch in s: # Look at each character in s
        result.append(ch)
    return result
        #result = result.append( ch )# Add each ch to our result list
        # ^ DONT DO THIS
        # We don't do result = result.append(x)
        # It's just result.append(x)
        # No result = because .append()
        # returns None

''' GEO.PY'''
def series( x, n ):
    result = [] # We want to build up a new list
    for i in range(0,n):
        term = (-x)**(i+1)
        result.append( term )
    return result

    # for i in range(1,n+1): # 1 to n
        # term = (-x)**(i)
        # result.append( term )
    # return result

''' RING.PY '''
def chomp( s, i, j ): # Three parameters
    prefix = s[ 0 : i ]
    suffix = s[ j :   ]
    result = prefix + suffix
    return result

# 'ABCDEFGHIJ'
#  0123456789
# s[0:i] -> s's characters from 0 to i - 1
# s[ j: ] -> s's characters from j onwards
# s[i:j] gets characters from index i to j-1
# Get slice[0:2] + slice[6:]
# -> 'AB' + 'GHIJ' -> 'ABGHIJ'

''' TAB.PY '''
def square( x ): # single dataset parameter x
    ''' Returns True if number of columns
    is equal to the number of rows in the
    dataset x'''
    # Recall a dataset is [[...],[...]]
    number_rows = len( x ) # number of
    # smaller lists (rows) in your outer list
    for row in x:
        number_columns_in_row = len( row )
        # if # of rows is not equal to # of columns
        # == is testing if they're equal
        # != is testing if they're NOT equal
        if ( number_columns_in_row != number_rows) :
            return False
        # else: # We don't want this!
                # It wouldn't look at the other rows.
            # return True (can do continue/pass)
    return True # We never found a row where
    # the number of columns didn't equal the
    # number of rows sooo we can return True :)

    # Remember that once you hit a return
    # statement, the rest of your code
    # isn't evaluated. Your function is
    # DONE once you hit a return statement.

''' DATE.PY '''
def avg( x ): # single dataset parameter x
    # sum(dataset) doesn't work!
    # Accumulators
    sum_dataset = 0
    nbr_values_in_dataset = 0

    for row in x: # Go through each row in the dataset
        sum_row = sum( row )    # Calculate this to add the sum of the row numbers to the sum accumulator
        nbr_row = len( row )    # Calculate this to Add the number of elements to the # values accumulator
        sum_dataset = sum_dataset + sum_row # Update sum accumulator
        nbr_values_in_dataset = nbr_values_in_dataset + nbr_row # Update
    average =  sum_dataset / nbr_values_in_dataset
    return average

# Remember that when you write your
# function definitions, make sure you just
# name the function the same name as our instructions
# and how many parameters / names of parameters
# matches the instruction description.
# "No parameters", "Three parameters", etc.

# No you will not write testers.
# You won't have to write the
# if __name__ == '__main___' part!
# Just write the functions and run them
# using the testers we provide.

# Please don't mess with testers.
# On the exam for the coding portion, you
# will be writing functions in modules
# that you can use OUR testers (provided)
# to run the code written in the modules.

''' TESTER '''
# This is the tester. YOU don't have to
# worry about writing this part.

# Just a way for us to check one function
# at a time.
check_dare = False
check_eval = False
check_up = False
check_swap = False
check_conv = False
check_series = False
check_chomp = False
check_square = False
check_avg = True
if ( __name__ == '__main__' ) :
    if ( check_dare == True ) :
        result = dare()
        print( result )
    if ( check_eval == True ):
        for c in ['+','-','*','%']:
            result = eval(2, c, 3)
            print( result )
    if ( check_up == True ):
        for s in ['abc','woah!']:
            result = up( s )
            print( result )
    if ( check_swap == True ):
        for s in ['ee cummings', 'CS 1112', 'aBcD']:
            result = swap( s )
            print( result )
    if ( check_conv == True ):
        for s in ['apple', 'banana']:
            result = conv( s )
            print( result )
    if ( check_series == True ):
        tests = [(2,5), (3,4)]
        for test in tests:
            x, n = test
            result = series( x, n )
            print( result )
    if ( check_chomp == True ):
        result = chomp('ABCDEFGHIJ', 2, 6)
        print( result )
    if ( check_square == True ):
        tests = [ [[2]], [[2, 4, 6]],  [[2], [4], [6]] ,  [[2, 4, 6], [1, 3, 5], [7, 8, 9]] ]
        for test in tests:
            result = square( test )
            print( result )

    if ( check_avg == True ):
        tests = [ [[1, 2]],  [[2, 4, 6], [8], [10, 12]] ]
        for test in tests:
            result = avg( test )
            print( result )