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Python Python Collections (Retired) Slices sillyCase

Posted by David Wright
David Wright
4,437 Points

I'm being silly on the SillyCase Challenge

Please, help with this silliness!

silly.py 
# The first half of the string, rounded with round(), should be lowercased.
# The second half should be uppercased.
# E.g. "Treehouse" should come back as "treeHOUSE"
def sillycase(string):
  string_length = len(string)
  half_string = string_length / 2
  first_half = string[:half_string]
  result = first_half.extend(string[half_string:])
  return result

3 Answers

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,423 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points

You are very close. A few corrections to you code. extend() works on lists but not on strings. 

def sillycase(string):
  string_length = len(string)
  # need to round when length is odd
  half_string = round(string_length / 2)
  first_half = string[:half_string]
  # lower first half and upper second half 
  result = first_half.lower() + string[half_string:].upper()
  return result
Innocent Ngwaru
Innocent Ngwaru
7,554 Points
Innocent Ngwaru
Innocent Ngwaru
7,554 Points

How abou this. Where am i wrong if I decide to use this method

def sillycase(input_string):
  pivot_index = [(len(input_string)+1)/2]
  char_list = [char.lower() if index < pivot else char.upper() for index, char in enumerate(input_string)]
  return sillycase(input_string.join(char_list))

[MOD: added ```python markdown formatting -cf]

Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points

Innocent, your code does not seem it pass. pivot isn't defined, the pivot value should be an int not a list, and the pivot value needs to adjust for 0-based indexing:

def sillycase(input_string):
    pivot = (len(input_string))/2
    char_list = [char.lower() if index <= pivot else char.upper() for index, char in enumerate(input_string)]
    return ''.join(char_list)

Your approach has an interesting list compression which works but might be less readable than using a simple list slice. It would be interesting to time it to see which is faster.

Innocent Ngwaru
Innocent Ngwaru
7,554 Points
Innocent Ngwaru
Innocent Ngwaru
7,554 Points

Thank you Chris. I took a leaf from your response above. I was doing it the hard way. Thank you!

Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points

After using timeit to compare your solution and the best answer, your code takes 3x more time:

import timeit

setup="""def sillycase(input_string):
    pivot = (len(input_string))/2
    char_list = [char.lower() if index <= pivot else char.upper() for index, char in enumerate(input_string)]
    return ''.join(char_list)
"""

setupBA = """def sillycaseOP(string):
  string_length = len(string)
  # need to round when length is odd
  half_string = round(string_length / 2)
  first_half = string[:half_string]
  # lower first half and upper second half 
  result = first_half.lower() + string[half_string:].upper()
  return result
  """

print( timeit.timeit(stmt="sillycaseBA('treehouse')", setup=setupBA, number=100000) )
print( timeit.timeit(stmt="sillycase('treehouse')", setup=setup, number=100000) )

3.149674166692421
10.27628900000127