Python Forum

Why print('Number of donuts: 9')==repr('Number of donuts: 9') is false? How to fix it to true?

print (left-hand side) returns None. Right-hand side repr returns string literal. This expression will never be True. Explain what you actually want to achieve.

(Oct-13-2018, 06:16 PM)buran Wrote: [ -> ]print (left-hand side) returns None. Right-hand side repr returns string literal. This expression will never be True. Explain what you actually want to achieve.

Thanks so much! I know where I am wrong. Here is what I am trying to do. Many mistakes and a lot to learn.


#!/usr/bin/python -tt
# Copyright 2010 Google Inc.
# Licensed under the Apache License, Version 2.0
# http://www.apache.org/licenses/LICENSE-2.0

# Google's Python Class
# http://code.google.com/edu/languages/goo...hon-class/

# Basic string exercises
# 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.
# It's ok if you do not complete all the functions, and there
# are some additional functions to try in string2.py.


# A. 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'
def donuts(count):
# +++your code here+++
if count<10:
print('Number of donuts: %d' %count)
else:
print('Number of donuts: many')

# B. 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):
# +++your code here+++
if len(s)>3:
end_string = s[0:1] + s[-2:-1]
elif len(s)<4 and len(s)>1:
end_string = s
else:
end_string = []
return end_string


# 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.
# 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# where all instances of stra have been replaced by strb.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):
# +++your code here+++
fix_rest = s[1:]
fix_rest_re = fix_rest.replace(fix_first,'*')
fix_string = s[0] + fix_rest_re
return fix_string


# D. 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):
# +++your code here+++
mix_string_1 = b[0:1] + a[2:]
mix_string_2 = a[0:1] + b[2:]
mix_string = mix_string_1 + ' ' + mix_string_2
return


# 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 ('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')


# Standard boilerplate to call the main() function.
if __name__ == '__main__':
main()

We are not going to do everything for you.
Note that your functions (e.g. donuts) need to return something, not print something.
Also please, use proper tags when post code, traceback, output, etc.
See BBcode help for more info.

(Oct-13-2018, 06:37 PM)buran Wrote: [ -> ]We are not going to do everything for you.
Note that your functions (e.g. donuts) need to return something, not print something.
Also please, use proper tags when post code, traceback, output, etc.
See BBcode help for more info.

I have fixed all the problems, and some problems are really naive. I am newbie in coding, and thanks so much for your suggestions!