This lab will let us know how to use String and use command of String and List. This show us how to cut a String or List, and get a new String, List. or we can split the string and then join them together. In list, we will use ‘append’. Finally, the program will test our program by checking our result with expected value, and give us the result as ‘OK’ or ‘X’.
Python code for Lab5:
# Lab5_Python4
# Students’ Names: HUY LY
# INSTRUCTIONS
# Fill in the code for the functions below. The main() fucntion is already set up
# to call the functions with a few different inputs,
# printing ‘OK’ when each function is correct and ‘X’ when wrong.
# The starter code for each function includes a ‘return’
# which is just a placeholder for your code.
#
# SUGGESTIONS
# 1.Run this starter program before you start coding anything, to get familiar with the tests.
# 2.Save this program as Lab5<your last names>.py (replace <your last names> with your lastnames.
# 4.Code one function and test it.
# 5.When the code of your function passes the test, work on the next function.
# 5.Repeat this until you complete all the functions and all of them pass the corresponding test.
# STRING FUNCTIONS
# 1.- cupcakes
# Given an int count of a number of cupcakes, return a string
# of the form ‘Number of cupcakes: <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 cupcakes(5) returns ‘Number of cupcakes: 5’
# and cupcakes(23) returns ‘Number of cupcakes: many’
def cupcakes(count):
if count<10:
return(‘Number of cupcakes: ‘+str(count))
else:
return(‘Number of cupcakes: many’)
# 2.- 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.
def both_ends(s):
if len(s)<=2:
return (”)
else:
name=s[0]+s[1]+s[len(s)-2]+s[len(s)-1]
return (name)
# 3.- 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.
# Hint: s.replace(stra, strb) returns a version of string s
# where all instances of stra have been replaced by strb.
def fix_start(s):
count=1
while len(s)>count:
if s[count]==s[0]:
letter=s[0]
s=s.replace(s[count],’*’)
s=letter+s[1:len(s)]
count+=1
return s
# 4.- 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.
def mix_up(a, b):
name=b[0:2]+a[2:]+’ ‘+a[0:2]+b[2:]
return (name)
# LIST FUNCTIONS
# 5.- 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.
# Note: python does not have a ++ operator, but += works.
# For example, the result of n = n + 1 can be also achieved by n += 1.
def match_ends(words):
count=0
num=0
while len(words)>count:
if len(words[count])>=2:
if words[count][0]==words[count][len(words[count])-1]:
num+=1
count+=1
return num
# 6.- 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’]
# Hint: this can be done by making 2 lists (i.e., xWords =[] and otherWords =[])
# and sorting each of them before combining them (i.e., xWords.sort()).
def front_x(words):
xWord=[]
otherWords=[]
num=0
while len(words)> num:
if words[num][0]==’x’:
xWord.append(words[num])
else:
otherWords.append(words[num])
num+=1
xWord.sort()
otherWords.sort()
return (xWord+otherWords)
# Provided simple 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 = ‘ X ‘
print (‘%s got: %s expected: %s’ % (prefix, repr(got), repr(expected)))
# Provided main() calls the above functions with interesting inputs,
# using test() to check if each result is correct or not.
def main():
print (‘cupcakes’)
# Each line calls cupcakes, compares its result to the expected for that call.
test(cupcakes(4), ‘Number of cupcakes: 4’)
test(cupcakes(9), ‘Number of cupcakes: 9’)
test(cupcakes(10), ‘Number of cupcakes: many’)
test(cupcakes(99), ‘Number of cupcakes: 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 (‘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’])
# Standard boilerplate to call the main() function.
if __name__ == ‘__main__’:
main()
