Re: [Tutor] Character Buffer Object Error
Always reply-all so a copy goes to the tutor list. On 2/8/2012 11:04 PM, Michael Lewis wrote: Thanks Bob, Thanks for what if you did not follow my suggestions? Your code is still pretty buggy. Please test it by running it, seeing that the result is not correct, then try the desk checking. The below code is what I came up with without using your suggestion. On a scale, how novice is mine compared to what you offered? I am curious because I want to know if I should have come up with your solution instead of what I did come up with. def AlterInput(user_input): '''search for nums in str and increment/append, return new string''' new_output = [] for num in user_input: if not num.isdigit(): new_output.append(num) else: num.isdigit() new_num = int(num) new_num += 1 new_output.append(str(new_num)) return ' '.join(new_output) def GetUserInput(): '''Get a string from the user and pass it''' user_input = '''I * got 432 when I counted, but Jim got 433 which is a lot for only 6 cats, or were there 12 cats?''' return AlterInput(user_input.split()) Your code: return ' '.join(str(int(num)+1) if num.isdigit() else num for num in user_input) On Wed, Feb 8, 2012 at 6:04 AM, bob gailer bgai...@gmail.com mailto:bgai...@gmail.com wrote: On 2/8/2012 12:56 AM, Michael Lewis wrote: I want to find all digits in a string and then increment those digits by 1 and then return the same string with the incremented digits. [snip] You got lots of good advice from others and some not-so-good advice. Michael said: 2. The following line appears wrong. new_output = ' '.join(user_input) He did not say why! I add: Master the art of Desk Checking. Take pencil paper. Write down the input and output of each statement as though you were the computer. Also learn to read the understand the Python Manuals: str.replace(old, new[, count]) Return a copy of the string with all occurrences of substring old replaced by new. If the optional argument count is given, only the first count occurrences are replaced. Notice return a copy. It does NOT say that this will convert old in place. No one else caught this problem! Since this is homework we we probably should not be offering alternative solutions. However I can't resist offering the one-line solution: ''.join(str(int(x)+1) if x.isdigit() else x for x in 'user_input) -- Bob Gailer 919-636-4239 tel:919-636-4239 Chapel Hill NC -- Bob Gailer 919-636-4239 Chapel Hill NC ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Character Buffer Object Error OOPS
On 2/8/2012 11:04 PM, Michael Lewis wrote: Thanks Bob, My Bad - I did not examine all your code - I broke my own rule. Your code is still a little buggy. The below code is what I came up with without using your suggestion. On a scale, how novice is mine compared to what you offered? I am curious because I want to know if I should have come up with your solution instead of what I did come up with. Since you are studying Python you do well to apply what you learn. The first objective is to get something that works. As you learn more you then apply new techniques. When you have learned conditional expressions, list comprehensions and generator expressions then you will be able to write the code I did. That code is just an alternative to what you wrote, flattening it as it were. [snip] -- Bob Gailer 919-636-4239 Chapel Hill NC ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Character Buffer Object Error
On Thu, Feb 9, 2012 at 2:43 PM, bob gailer bgai...@gmail.com wrote: Always reply-all so a copy goes to the tutor list. On 2/8/2012 11:04 PM, Michael Lewis wrote: Thanks Bob, Thanks for what if you did not follow my suggestions? I partially followed your suggestions by getting rid of str.replace(old, new[, count]) and new_output = ' '.join(user_input). But I also wanted to try to get this to work without simply copying your code. Your code is still pretty buggy. I don't think I made my intentions clear. I don't wont to increment each digit. I want to find each number (for example, if the str contains 436, I don't want to interpret that as 4, 3, 6 - I instead want to interpret that as 436, which is why I created a list and then joined back into a string afterwards. Please test it by running it, seeing that the result is not correct, then try the desk checking. I don't see how this is not correct, because my input was I got 432 when I counted, but Jim got 433 which is a lot for only 6 cats, or were there 12 cats? And my output was: I got 433 when I counted, but Jim got 434 which is a lot for only 7 cats, or were there 13 cats? The below code is what I came up with without using your suggestion. On a scale, how novice is mine compared to what you offered? I am curious because I want to know if I should have come up with your solution instead of what I did come up with. def AlterInput(user_input): '''search for nums in str and increment/append, return new string''' new_output = [] for num in user_input: if not num.isdigit(): new_output.append(num) else: num.isdigit() new_num = int(num) new_num += 1 new_output.append(str(new_num)) return ' '.join(new_output) def GetUserInput(): '''Get a string from the user and pass it''' user_input = '''I * got 432 when I counted, but Jim got 433 which is a lot for only 6 cats, or were there 12 cats?''' return AlterInput(user_input.split()) Your code: return ' '.join(str(int(num)+1) if num.isdigit() else num for num in user_input) ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Character Buffer Object Error
On 08/02/12 05:56, Michael Lewis wrote: I've tried the following code, but I am getting the following error. How do I do this properly? Christian answered the reason for the error. Here are some other comments... def AlterInput(user_input): print user_input new_output = '' make this a list not a string for index, char in enumerate(user_input): you don;t need index or enumerate just a simple for loop. if char.isdigit(): new_char = int(char) new_char += 1 How will you handle 9? Insert 10 or lose the 1 (or the zero?) Your choice... I'll assume you insert 10 new_output = ' '.join(user_input) I gave no idea what this is for, why insert spaces? Instead append new_char as a str to the list new_output.append(str(new_char)) This needs to be outside the if statement because you want to add all the chars. You will need to play with the assignments to make that work but it should be a lot simpler... At the very end join the list back to a string: return ''.join(new_output) new_output.replace(char, new_char) You don't need this with a list print new_output Best to keep print statements outside the function and just return the value AlterInput(user_input.split()) You don't need to split, just pass in the users string. HTH, -- Alan G Author of the Learn to Program web site http://www.alan-g.me.uk/ ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Character Buffer Object Error
On 2/8/2012 12:56 AM, Michael Lewis wrote: I want to find all digits in a string and then increment those digits by 1 and then return the same string with the incremented digits. [snip] You got lots of good advice from others and some not-so-good advice. Michael said: 2. The following line appears wrong. new_output = ' '.join(user_input) He did not say why! I add: Master the art of Desk Checking. Take pencil paper. Write down the input and output of each statement as though you were the computer. Also learn to read the understand the Python Manuals: str.replace(old, new[, count]) Return a copy of the string with all occurrences of substring old replaced by new. If the optional argument count is given, only the first count occurrences are replaced. Notice return a copy. It does NOT say that this will convert old in place. No one else caught this problem! Since this is homework we we probably should not be offering alternative solutions. However I can't resist offering the one-line solution: ''.join(str(int(x)+1) if x.isdigit() else x for x in 'user_input) -- Bob Gailer 919-636-4239 Chapel Hill NC ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
[Tutor] Character Buffer Object Error
I want to find all digits in a string and then increment those digits by 1 and then return the same string with the incremented digits. I've tried the following code, but I am getting the following error. How do I do this properly? def AlterInput(user_input): print user_input new_output = '' for index, char in enumerate(user_input): if char.isdigit(): new_char = int(char) new_char += 1 new_output = ' '.join(user_input) new_output.replace(char, new_char) print new_output def GetUserInput(): '''Get a string from the user and pass it''' user_input = '''I got 432 when I counted, but Jim got 433 which is a lot for only 6 cats, or were there 12 cats?''' AlterInput(user_input.split()) Traceback (most recent call last): File C:/Python27/Homework/Homework 4_1.py, line 25, in module GetUserInput() File C:/Python27/Homework/Homework 4_1.py, line 23, in GetUserInput AlterInput(user_input.split()) File C:/Python27/Homework/Homework 4_1.py, line 15, in AlterInput new_output.replace(char, new_char) TypeError: expected a character buffer object Thanks. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Character Buffer Object Error
On 2012/02/08 07:56 AM, Michael Lewis wrote: I want to find all digits in a string and then increment those digits by 1 and then return the same string with the incremented digits. I've tried the following code, but I am getting the following error. How do I do this properly? def AlterInput(user_input): print user_input new_output = '' for index, char in enumerate(user_input): if char.isdigit(): new_char = int(char) new_char += 1 new_output = ' '.join(user_input) new_output.replace(char, new_char) print new_output def GetUserInput(): '''Get a string from the user and pass it''' user_input = '''I got 432 when I counted, but Jim got 433 which is a lot for only 6 cats, or were there 12 cats?''' AlterInput(user_input.split()) Traceback (most recent call last): File C:/Python27/Homework/Homework 4_1.py, line 25, in module GetUserInput() File C:/Python27/Homework/Homework 4_1.py, line 23, in GetUserInput AlterInput(user_input.split()) File C:/Python27/Homework/Homework 4_1.py, line 15, in AlterInput new_output.replace(char, new_char) TypeError: expected a character buffer object Thanks. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor new_char is of type int and not type str, so cast it back to a string before using it in your call to .replace as it expects both arguments to be strings. -- Christian Witts Python Developer // ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Character Buffer Object Error
Dear Michael Overall I see a few problems. 0. Functions should return values. Not print them 1. Why use enumerate? The code is not using the index anyway 2. The following line appears wrong. new_output = ' '.join(user_input) 3. This line has a very buggy possibility. new_output.replace(char, new_char) Let us say you have 234. First time you will replace 2 with 3, getting 334. And then you will replace the first 3 with 4 getting 434 and finally end up with 534. Of course due to other coding errors this does not come to pass. But your basic idea of using str.replace() is prone to this problem. 4. How are you supposed to treat 9? Anyway back to your problem: I want to find all digits in a string and then increment those digits by 1 and then return the same string with the incremented digits. Pseudocode -- Initialise and outstring (empty) Read the instring character by character if the current character is not a digit append it to outstring else append the transform(current char) to outstring If you can organize your code like this it may be easier HTH Regards Asokan Pichai ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
