#!/usr/bin/python -tt
# Original Copywrites: Google Inc.
# Original licence: Apache License, Version 2.0
# http://www.apache.org/licenses/LICENSE-2.0
#
# Source:
# http://stoma.name
# Tasks primary created by Nick Parlante
# Later revisited and regrouped by Szymon Stoma.
# Fill in the code for the functions below. main() is already set up
# to call the functions with a few different inputs,
# printing 'OK' when each function is correct.
# The starter code for each function includes a 'return'
# which is just a placeholder for your code.
# A. match_ends
# Given a list of strings, return the count of the number of
# strings where the string length is 2 or more and the first
# and last chars of the string are the same.
#
# HINTS:
# 1. string manipulations - we assume that s = 'abcde', then:
# s[0] # 'a' first element
# s[-1] # 'e' last element
# s[1:2] # 'b' all elements between first (inc.) and second (exc.)
# s[2:] # 'cde' all elements after second element
#
# 2. python does not have a ++ operator, but += works.
#
# 3. for each element of list i do sth.:
# l = []
# for i in l:
# print i
#
# 4. len(l) return the number of elements in l (work both for list, strings, more...)
def match_ends(words):
# +++your code here+++
return
# B. front_x
# Given a list of strings, return a list with the strings
# in sorted order, except group all the strings that begin with 'x' first.
# e.g. ['mix', 'xyz', 'apple', 'xanadu', 'aardvark'] yields
# ['xanadu', 'xyz', 'aardvark', 'apple', 'mix']
#
# HINTS:
# 1. this can be done by making 2 lists and sorting each of them
# before combining them.
#
# 2. To sort a list l type: l.sort() or sorted( l ) (first is method altering
# list, second a function returning a new sorted list) ;)
#
# 3. To append string 'ab' to a list l use: l.append('ab')
def front_x(words):
# +++your code here+++
return
# C. sort_last
# Given a list of non-empty tuples, return a list sorted in increasing
# order by the last element in each tuple.
# e.g. [(1, 7), (1, 3), (3, 4, 5), (2, 2)] yields
# [(2, 2), (1, 3), (3, 4, 5), (1, 7)]
#
# HINTS
# 1. use a custom key= function to extract the last element form each tuple.
# l.sort(key=...)
#
# 2. remember that you may define a function inside a function like this:
# def f(a):
# def mult(a,b):
# return a*b
# return mult(a,a)
def sort_last(tuples):
# +++your code here+++
return
# D. Given a list of numbers, return a list where
# all adjacent == elements have been reduced to a single element,
# so [1, 2, 2, 3] returns [1, 2, 3]. You may create a new list or
# modify the passed in list.
def remove_adjacent(nums):
# +++your code here+++
return
# E. donuts
# Given an int count of a number of donuts, return a string
# of the form 'Number of donuts: <count>', where <count> is the number
# passed in. However, if the count is 10 or more, then use the word 'many'
# instead of the actual count.
# So donuts(5) returns 'Number of donuts: 5'
# and donuts(23) returns 'Number of donuts: many'
#
# HINTS:
# 1. You should use if construction:
# if x < 5:
# print 'small'
# else:
# print 'big..'
#
# 2. To concatenate strings use +
# a = 'aa'
# b = 'bb'
# c = a+b # 'aabb'
def donuts(count):
# +++your code here+++
return
# F. both_ends
# Given a string s, return a string made of the first 2
# and the last 2 chars of the original string,
# so 'spring' yields 'spng'. However, if the string length
# is less than 2, return instead the empty string.
#
# HINTS:
# 1. string manipulations - we assume that s = 'abcde', then:
# s[0] # 'a' first element
# s[-1] # 'e' last element
# s[1:2] # 'b' all elements between first (inc.) and second (exc.)
# s[2:] # 'cde' all elements after second element
#
# 2. Empty string is ''
def both_ends(s):
# +++your code here+++
return
# C. fix_start
# Given a string s, return a string
# where all occurences of its first char have
# been changed to '*', except do not change
# the first char itself.
# e.g. 'babble' yields 'ba**le'
# Assume that the string is length 1 or more.
#
# HINTS:
# 1. s.replace(stra, strb) returns a version of string s
# where all instances of stra have been replaced by strb.
#
# 2. Again look at the specification of string operations from previous ex.
def fix_start(s):
# +++your code here+++
return
# G. MixUp
# Given strings a and b, return a single string with a and b separated
# by a space '<a> <b>', except swap the first 2 chars of each string.
# e.g.
# 'mix', pod' -> 'pox mid'
# 'dog', 'dinner' -> 'dig donner'
# Assume a and b are length 2 or more.
#
# HINTS:
# 1. Again look at the specification of string operations from previous ex.
def mix_up(a, b):
# +++your code here+++
return
# E. verbing
# Given a string, if its length is at least 3,
# add 'ing' to its end.
# Unless it already ends in 'ing', in which case
# add 'ly' instead.
# If the string length is less than 3, leave it unchanged.
# Return the resulting string.
def verbing(s):
# +++your code here+++
return
# F. not_bad
# Given a string, find the first appearance of the
# substring 'not' and 'bad'. If the 'bad' follows
# the 'not', replace the whole 'not'...'bad' substring
# with 'good'.
# Return the resulting string.
# So 'This dinner is not that bad!' yields:
# This dinner is good!
def not_bad(s):
# +++your code here+++
return
# G. front_back
# Consider dividing a string into two halves.
# If the length is even, the front and back halves are the same length.
# If the length is odd, we'll say that the extra char goes in the front half.
# e.g. 'abcde', the front half is 'abc', the back half 'de'.
# Given 2 strings, a and b, return a string of the form
# a-front + b-front + a-back + b-back
def front_back(a, b):
# +++your code here+++
return
# Simple provided test() function used in main() to print
# what each function returns vs. what it's supposed to return.
def test(got, expected):
if got == expected:
prefix = ' OK '
else:
prefix = ' FAIL '
print '%s got: %s expected: %s' % (prefix, repr(got), repr(expected))
# Calls the above functions with interesting inputs.
def main():
print 'match_ends'
test(match_ends(['aba', 'xyz', 'aa', 'x', 'bbb']), 3)
test(match_ends(['', 'x', 'xy', 'xyx', 'xx']), 2)
test(match_ends(['aaa', 'be', 'abc', 'hello']), 1)
print
print 'front_x'
test(front_x(['bbb', 'ccc', 'axx', 'xzz', 'xaa']),
['xaa', 'xzz', 'axx', 'bbb', 'ccc'])
test(front_x(['ccc', 'bbb', 'aaa', 'xcc', 'xaa']),
['xaa', 'xcc', 'aaa', 'bbb', 'ccc'])
test(front_x(['mix', 'xyz', 'apple', 'xanadu', 'aardvark']),
['xanadu', 'xyz', 'aardvark', 'apple', 'mix'])
print
print 'sort_last'
test(sort_last([(1, 3), (3, 2), (2, 1)]),
[(2, 1), (3, 2), (1, 3)])
test(sort_last([(2, 3), (1, 2), (3, 1)]),
[(3, 1), (1, 2), (2, 3)])
test(sort_last([(1, 7), (1, 3), (3, 4, 5), (2, 2)]),
[(2, 2), (1, 3), (3, 4, 5), (1, 7)])
print
print 'remove_adjacent'
test(remove_adjacent([1, 2, 2, 3]), [1, 2, 3])
test(remove_adjacent([2, 2, 3, 3, 3]), [2, 3])
test(remove_adjacent([]), [])
print
print 'donuts'
# Each line calls donuts, compares its result to the expected for that call.
test(donuts(4), 'Number of donuts: 4')
test(donuts(9), 'Number of donuts: 9')
test(donuts(10), 'Number of donuts: many')
test(donuts(99), 'Number of donuts: many')
print
print 'both_ends'
test(both_ends('spring'), 'spng')
test(both_ends('Hello'), 'Helo')
test(both_ends('a'), '')
test(both_ends('xyz'), 'xyyz')
print
print 'fix_start'
test(fix_start('babble'), 'ba**le')
test(fix_start('aardvark'), 'a*rdv*rk')
test(fix_start('google'), 'goo*le')
test(fix_start('donut'), 'donut')
print
print 'mix_up'
test(mix_up('mix', 'pod'), 'pox mid')
test(mix_up('dog', 'dinner'), 'dig donner')
test(mix_up('gnash', 'sport'), 'spash gnort')
test(mix_up('pezzy', 'firm'), 'fizzy perm')
print
print 'verbing'
test(verbing('hail'), 'hailing')
test(verbing('swiming'), 'swimingly')
test(verbing('do'), 'do')
print
print 'not_bad'
test(not_bad('This movie is not so bad'), 'This movie is good')
test(not_bad('This dinner is not that bad!'), 'This dinner is good!')
test(not_bad('This tea is not hot'), 'This tea is not hot')
test(not_bad("It's bad yet not"), "It's bad yet not")
print
print 'front_back'
test(front_back('abcd', 'xy'), 'abxcdy')
test(front_back('abcde', 'xyz'), 'abcxydez')
test(front_back('Kitten', 'Donut'), 'KitDontenut')
if __name__ == '__main__':
main()
# Original Copywrites: Google Inc.
# Original licence: Apache License, Version 2.0
# http://www.apache.org/licenses/LICENSE-2.0
#
# Source:
# http://stoma.name
# Tasks primary created by Nick Parlante
# Later revisited and regrouped by Szymon Stoma.
# Fill in the code for the functions below. main() is already set up
# to call the functions with a few different inputs,
# printing 'OK' when each function is correct.
# The starter code for each function includes a 'return'
# which is just a placeholder for your code.
# A. match_ends
# Given a list of strings, return the count of the number of
# strings where the string length is 2 or more and the first
# and last chars of the string are the same.
#
# HINTS:
# 1. string manipulations - we assume that s = 'abcde', then:
# s[0] # 'a' first element
# s[-1] # 'e' last element
# s[1:2] # 'b' all elements between first (inc.) and second (exc.)
# s[2:] # 'cde' all elements after second element
#
# 2. python does not have a ++ operator, but += works.
#
# 3. for each element of list i do sth.:
# l = []
# for i in l:
# print i
#
# 4. len(l) return the number of elements in l (work both for list, strings, more...)
def match_ends(words):
# +++your code here+++
return
# B. front_x
# Given a list of strings, return a list with the strings
# in sorted order, except group all the strings that begin with 'x' first.
# e.g. ['mix', 'xyz', 'apple', 'xanadu', 'aardvark'] yields
# ['xanadu', 'xyz', 'aardvark', 'apple', 'mix']
#
# HINTS:
# 1. this can be done by making 2 lists and sorting each of them
# before combining them.
#
# 2. To sort a list l type: l.sort() or sorted( l ) (first is method altering
# list, second a function returning a new sorted list) ;)
#
# 3. To append string 'ab' to a list l use: l.append('ab')
def front_x(words):
# +++your code here+++
return
# C. sort_last
# Given a list of non-empty tuples, return a list sorted in increasing
# order by the last element in each tuple.
# e.g. [(1, 7), (1, 3), (3, 4, 5), (2, 2)] yields
# [(2, 2), (1, 3), (3, 4, 5), (1, 7)]
#
# HINTS
# 1. use a custom key= function to extract the last element form each tuple.
# l.sort(key=...)
#
# 2. remember that you may define a function inside a function like this:
# def f(a):
# def mult(a,b):
# return a*b
# return mult(a,a)
def sort_last(tuples):
# +++your code here+++
return
# D. Given a list of numbers, return a list where
# all adjacent == elements have been reduced to a single element,
# so [1, 2, 2, 3] returns [1, 2, 3]. You may create a new list or
# modify the passed in list.
def remove_adjacent(nums):
# +++your code here+++
return
# E. donuts
# Given an int count of a number of donuts, return a string
# of the form 'Number of donuts: <count>', where <count> is the number
# passed in. However, if the count is 10 or more, then use the word 'many'
# instead of the actual count.
# So donuts(5) returns 'Number of donuts: 5'
# and donuts(23) returns 'Number of donuts: many'
#
# HINTS:
# 1. You should use if construction:
# if x < 5:
# print 'small'
# else:
# print 'big..'
#
# 2. To concatenate strings use +
# a = 'aa'
# b = 'bb'
# c = a+b # 'aabb'
def donuts(count):
# +++your code here+++
return
# F. both_ends
# Given a string s, return a string made of the first 2
# and the last 2 chars of the original string,
# so 'spring' yields 'spng'. However, if the string length
# is less than 2, return instead the empty string.
#
# HINTS:
# 1. string manipulations - we assume that s = 'abcde', then:
# s[0] # 'a' first element
# s[-1] # 'e' last element
# s[1:2] # 'b' all elements between first (inc.) and second (exc.)
# s[2:] # 'cde' all elements after second element
#
# 2. Empty string is ''
def both_ends(s):
# +++your code here+++
return
# C. fix_start
# Given a string s, return a string
# where all occurences of its first char have
# been changed to '*', except do not change
# the first char itself.
# e.g. 'babble' yields 'ba**le'
# Assume that the string is length 1 or more.
#
# HINTS:
# 1. s.replace(stra, strb) returns a version of string s
# where all instances of stra have been replaced by strb.
#
# 2. Again look at the specification of string operations from previous ex.
def fix_start(s):
# +++your code here+++
return
# G. MixUp
# Given strings a and b, return a single string with a and b separated
# by a space '<a> <b>', except swap the first 2 chars of each string.
# e.g.
# 'mix', pod' -> 'pox mid'
# 'dog', 'dinner' -> 'dig donner'
# Assume a and b are length 2 or more.
#
# HINTS:
# 1. Again look at the specification of string operations from previous ex.
def mix_up(a, b):
# +++your code here+++
return
# E. verbing
# Given a string, if its length is at least 3,
# add 'ing' to its end.
# Unless it already ends in 'ing', in which case
# add 'ly' instead.
# If the string length is less than 3, leave it unchanged.
# Return the resulting string.
def verbing(s):
# +++your code here+++
return
# F. not_bad
# Given a string, find the first appearance of the
# substring 'not' and 'bad'. If the 'bad' follows
# the 'not', replace the whole 'not'...'bad' substring
# with 'good'.
# Return the resulting string.
# So 'This dinner is not that bad!' yields:
# This dinner is good!
def not_bad(s):
# +++your code here+++
return
# G. front_back
# Consider dividing a string into two halves.
# If the length is even, the front and back halves are the same length.
# If the length is odd, we'll say that the extra char goes in the front half.
# e.g. 'abcde', the front half is 'abc', the back half 'de'.
# Given 2 strings, a and b, return a string of the form
# a-front + b-front + a-back + b-back
def front_back(a, b):
# +++your code here+++
return
# Simple provided test() function used in main() to print
# what each function returns vs. what it's supposed to return.
def test(got, expected):
if got == expected:
prefix = ' OK '
else:
prefix = ' FAIL '
print '%s got: %s expected: %s' % (prefix, repr(got), repr(expected))
# Calls the above functions with interesting inputs.
def main():
print 'match_ends'
test(match_ends(['aba', 'xyz', 'aa', 'x', 'bbb']), 3)
test(match_ends(['', 'x', 'xy', 'xyx', 'xx']), 2)
test(match_ends(['aaa', 'be', 'abc', 'hello']), 1)
print 'front_x'
test(front_x(['bbb', 'ccc', 'axx', 'xzz', 'xaa']),
['xaa', 'xzz', 'axx', 'bbb', 'ccc'])
test(front_x(['ccc', 'bbb', 'aaa', 'xcc', 'xaa']),
['xaa', 'xcc', 'aaa', 'bbb', 'ccc'])
test(front_x(['mix', 'xyz', 'apple', 'xanadu', 'aardvark']),
['xanadu', 'xyz', 'aardvark', 'apple', 'mix'])
print 'sort_last'
test(sort_last([(1, 3), (3, 2), (2, 1)]),
[(2, 1), (3, 2), (1, 3)])
test(sort_last([(2, 3), (1, 2), (3, 1)]),
[(3, 1), (1, 2), (2, 3)])
test(sort_last([(1, 7), (1, 3), (3, 4, 5), (2, 2)]),
[(2, 2), (1, 3), (3, 4, 5), (1, 7)])
print 'remove_adjacent'
test(remove_adjacent([1, 2, 2, 3]), [1, 2, 3])
test(remove_adjacent([2, 2, 3, 3, 3]), [2, 3])
test(remove_adjacent([]), [])
print 'donuts'
# Each line calls donuts, compares its result to the expected for that call.
test(donuts(4), 'Number of donuts: 4')
test(donuts(9), 'Number of donuts: 9')
test(donuts(10), 'Number of donuts: many')
test(donuts(99), 'Number of donuts: many')
print 'both_ends'
test(both_ends('spring'), 'spng')
test(both_ends('Hello'), 'Helo')
test(both_ends('a'), '')
test(both_ends('xyz'), 'xyyz')
print 'fix_start'
test(fix_start('babble'), 'ba**le')
test(fix_start('aardvark'), 'a*rdv*rk')
test(fix_start('google'), 'goo*le')
test(fix_start('donut'), 'donut')
print 'mix_up'
test(mix_up('mix', 'pod'), 'pox mid')
test(mix_up('dog', 'dinner'), 'dig donner')
test(mix_up('gnash', 'sport'), 'spash gnort')
test(mix_up('pezzy', 'firm'), 'fizzy perm')
print 'verbing'
test(verbing('hail'), 'hailing')
test(verbing('swiming'), 'swimingly')
test(verbing('do'), 'do')
print 'not_bad'
test(not_bad('This movie is not so bad'), 'This movie is good')
test(not_bad('This dinner is not that bad!'), 'This dinner is good!')
test(not_bad('This tea is not hot'), 'This tea is not hot')
test(not_bad("It's bad yet not"), "It's bad yet not")
print 'front_back'
test(front_back('abcd', 'xy'), 'abxcdy')
test(front_back('abcde', 'xyz'), 'abcxydez')
test(front_back('Kitten', 'Donut'), 'KitDontenut')
if __name__ == '__main__':
main()