[Tutor] Doing this in reverse?
I found a script at http://code.activestate.com/recipes/65212/ that allows you to convert base 10 numbers to another base. I would like to convert non-base10 numbers to base 10. I wonder if I can do so by flipping the script around a bit: # (Lovingly) ripped off from a reply to the post at # http://code.activestate.com/recipes/65212/ # The function code is from that page # User Interface + comments created by Alan Gilfoy, 2007-2008 def baseconvert(n, base): """convert positive decimal integer n to equivalent in another base (2-36)""" digits = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ" # a thru z only apply in base 11 and up. # base 11 uses only a, base 12 uses a thru b, base 13 uses a thru c, and so on. # 'a' is equivalent to '10' in decimal, 'b' is equivalent to '11', etc. try: n = int(n) base = int(base) except: return "" if n < 0 or base < 2 or base > 36: return "" s = "" while 1: r = n % base s = digits[r] + s n = n / base if n == 0: break return s I'm not entirely sure how this works; I just know that it does. It looks like the program goes through a loop that "chops away" at the inputted number, gradually adding to the outputted number as appropriate. And what exactly does the % operator mean? ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Having trouble with a component of the random module
In this case, I was trying to pull 1 card from a 5-card pool, which should have worked. There was a typo in my code that I have since fixed, and it is working. I have to make sure manually that I'm not telling the program to pick more cards than exist in the list. I can do this two ways: Make the list long enough, and tell the selector function to pick a small enough amount from that pool. The following is not related to my code per se, but rather to an aspect of MTG booster packs that I have successfully replicated: In most cases, every common appears at the same frequency as every other common, so I normally put each name on the commons list exactly once. (and so on for other lists/other rarity levels) Thus, each card will be displayed only once per pack, unless I repeat the same name in the source list multiple times. (The program sees those repetitions as different entities.) Quoting OmerT <[EMAIL PROTECTED]>: Bob, Kent, I understood all that from the context and yet do not feel familiar enough with the information nor had the time to lookup. The point I'm making is that Alan has a logical problem with his generator regarding the question of repetitive cards in a booster: On one hand, the script does not allow to repeat cards. On the other- he tries to display 8 cards out of a 5 card pool, which is impossible without repeating cards. That's all.. On Sun, Aug 31, 2008 at 4:00 PM, bob gailer <[EMAIL PROTECTED]> wrote: OmerT wrote: I'm unfamiliar with the random.sample function, yet I can't help but wonder: Do you ever got the same card twice? Quoting the manual: sample( population, k) Return a k length list of unique elements chosen from the population sequence. Used for random sampling without replacement. -- Bob Gailer Chapel Hill NC 919-636-4239 When we take the time to be aware of our feelings and needs we have more satisfying interatctions with others. Nonviolent Communication provides tools for this awareness. As a coach and trainer I can assist you in learning this process. What is YOUR biggest relationship challenge? ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Having trouble with a component of the random module
I shouldn't get the same card twice in the same batch, no. Of course, in separate trials, I may get the same card again. Basically, I type the names of relevant cards in a list, and proceed to "tell" my program which list to read, and how many cards to pick from that list. Normally, I put each card name in the list only once. But if I type the same card name twice, the program sees the repetitions as different entities, and may display both of 'em if the randomness works out that way. random.sample I think runs dependent trials (the first pick affects the odds of the second pick, etc.) - kind of like pulling tickets from a hat. This is as opposed to independent random trials a la dice rolling. Someone correct me if I'm wrong on this - for this application, I want dependent trials. Quoting OmerT <[EMAIL PROTECTED]>: I'm unfamiliar with the random.sample function, yet I can't help but wonder: Do you ever got the same card twice? Is that intentional ? ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] It works! (my booster pack generator)
Yeah, I did a lot of python work for my high school's Senior Project (so, spring 2007); hadn't coded much since then, was rusty on the "pritn stattements for debugging" part. And I was trying to look at the code mentioned in the traceback, but due to my own mistake, I hadn't detected the problems with the lines that the traceback was pointing to. Quoting Kent Johnson <[EMAIL PROTECTED]>: On Thu, Aug 28, 2008 at 11:49 AM, Alan Gilfoy <[EMAIL PROTECTED]> wrote: The booster pack generator (my use of random.sample as described in a previous message) is working as intended now. There was a rather stupid typo in my code that was causing it to go wonky. Y'all still helped, though. A few people replied, but a bit of advice from: W W <[EMAIL PROTECTED]> pointed me in the right direction. As well as the lesson about using print statements to debug, I hope you have learned to believe the interpreters error messages. It usually knows what it is talking about :-) Kent ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] It works! (my booster pack generator)
The booster pack generator (my use of random.sample as described in a
previous message) is working as intended now.
There was a rather stupid typo in my code that was causing it to go wonky.
Y'all still helped, though. A few people replied, but a bit of advice
from: W W <[EMAIL PROTECTED]> pointed me in the right direction.
for card in random.sample(SpecialA, SA):
print card
he suggested changing to:
print "Special: ", SpecialA, "\nSA: ", SA
for card in random.sample(SpecialA, SA):
print card
Basically, what my program was doing:
1. Take a textfile, import it/convert it to a list via
open("filename.txt).readlines() This list was defined as the variable
"SpecialA_list".
2. Feed SpecialA_list, along with some other variables, into my function
3. "SpecialA" variable is set equal to a list consisting of items from
"SpecialA_list"
4. Then sample from "SpecialA" & print the results.
Thanks to the print statement that WW suggested, I figured out that
the "SpecialA" variable was coming out as an empty list. [error in
Step 3 of the above process list, so Step 4 had nothing to sample
*from*, thus triggering the traceback].
I found the typo that was causing this, and fixed it. So, the SpecialA
variable was set equal to the expected list, so random.sample could
sample properly.
Thank you. :)
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Re: [Tutor] Having trouble with a component of the random module
Quoting W W <[EMAIL PROTECTED]>: The number of items I want from a list is smaller than the population (number of items) in the list, so it should work. In this specific case, I'm asking for one item from a five-item list. Are you sure? change this: for card in random.sample(SpecialA, SA): to this: print "Special: ", SpecialA, "\nSA: ", SA for card in random.sample(SpecialA, SA): then give us the output. I'll bet that your SA value is never reset to 1. There is a part of my front-end code that declares the SA variable as equal to 1 for the card set in question, and feeds that into the processing function. Changing the block of code, as you suggest, still gets me a traceback: Special: [] SA: 1 Traceback (most recent call last): File "C:\Documents and Settings\Alan\My Documents\_Alan_Programming\trunk\BoosterPackMaker\BoosterPackMaker.py", line 104, in SixList_PackChooser(C_list, UC_list, R_list, BL_list, SpecialA_list, SpecialB_list, C, UC, R, BL, SA, SB) File "C:\Documents and Settings\Alan\My Documents\_Alan_Programming\trunk\BoosterPackMaker\PackGenerator.py", line 367, in SixList_PackChooser for card in random.sample(SpecialA, SA): File "C:\Python25\lib\random.py", line 303, in sample raise ValueError, "sample larger than population" ValueError: sample larger than population So, I'm asking my program to pick 1 item from a 0-item list. How there are zero items in the list, I don't know. That must be the problem. You've obviously researched enough to know this: mylist = [1, 2, 3, 4, 5] from random import sample sample(mylist, 3) [2, 1, 4] sample(mylist, 10) Traceback (most recent call last): File "", line 1, in File "/usr/lib/python2.5/random.py", line 303, in sample raise ValueError, "sample larger than population" ValueError: sample larger than population Okay, asking for 3 items from a 5-item list works, and asking for 10 items from a 5-item list doesn't work. It should be trying to pick 1 item from the 5-item SpecialA list, but somehow the SpecialA list has zero items in it. So give the print statement before your for loop a try and see what you come up with. Okay, I cut'n'pasted it before the traceback message. HTH, Wayne Thank you. --- SixList_PackChooser(C_list, UC_list, R_list, BL_list, SpecialA_list, SpecialB_list, C, UC, R, BL, SA, SB) ^ The error occurs in this function. The program picks C number of items from C_list and displays them just fine. The program picks UC number of items from UC_list and displays them just fine. The program picks R number of items from R_list and displays them just fine. The program picks BL number of items from BL_list and displays them just fine. Looking at my user-interface/front-end, it looks like the function's being fed proper values. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Having trouble with a component of the random module
One of my for-fun Python products is a booster-pack generator for
trading card games (specifically, Magic the Gathering, the one game of
the genre that I play heavily)
Somewhat like baseball cards, the cards in a pack are a
somewhat-random selection of cards from the set in question, broken
down by rarity levels.
There are anywhere from two to six rarity levels/groupings per set;
this depends on the set in question.
I have a function for 2-list sets, another for 3, another for 4,
another for 5, and another for 6.
By lists I mean the following: If a set has, say, 2 rarity levels in
it, I make 2 lists, one per rarity level. Each list is a text file
that has the names of each card of that rarity level in that set, one
per line. (There are no blank lines.)
My function is set up kind of like this: Import the lists - via
open("filename.txt").readlines()
This action creates a List, with strings as the list elements, one
string/element for each line of the imported text file
I use random.sample to make the selection, random.sample(population, k)
"
for card in random.sample(Common, C):
print card
"
Common is the 1st list, with the names of the commons in the set as
the items in that list. The C variable is an integer, the amount of
commons in a booster pack of that set. Say, if there are 11 commons in
a booster pack of that set, I feed 11 as the value for C, and the code
snippet above proceeds to print 11 randomly-selected names from the
Commons list
My program does the same thing for the second list (Uncommon), the
third list (Rare), the fourth list (BasicLand), the fifth list
(SpecialA), and the sixth list (SpecialB).
For card sets that use two, three, or four lists, the results are
displayed just fine.
For card sets that use five or six lists, the results for the first
four are displayed just fine, and then I get this:
The code that processes the 1st, 2nd, 3rd and 4th lists is very
similar to the code that processes the 5th and 6th, so I don't see
what's happening.
Traceback (most recent call last):
File "C:\Documents and Settings\Alan\My
Documents\_Alan_Programming\trunk\BoosterPackMaker\BoosterPackMaker.py", line
104, in
SixList_PackChooser(C_list, UC_list, R_list, BL_list,
SpecialA_list, SpecialB_list, C, UC, R, BL, SA, SB)
File "C:\Documents and Settings\Alan\My
Documents\_Alan_Programming\trunk\BoosterPackMaker\PackGenerator.py",
line 367, in SixList_PackChooser
for card in random.sample(SpecialA, SA):
File "C:\Python25\lib\random.py", line 303, in sample
raise ValueError, "sample larger than population"
ValueError: sample larger than population
Looking at the mentioned line in random.py, I don't see how my program
is triggering the ValueError.
The number of items I want from a list is smaller than the population
(number of items) in the list, so it should work.
In this specific case, I'm asking for one item from a five-item list.
Overall, more code is involved that I think can be represented in a
few cut'n'paste snippets; how would I go about providing the files in
question for interested parties to look at?
(There's the Python file for my front-end UI code, the Python module
file for my processing function, and the relevant text files)
Apologizing for message length; I'm just trying to clearly explain the
problem that I want assistance on.
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[Tutor] file(), open()
I want to work with simple ASCII text files, here.. I know you get them loaded into Python with file() or open() The arguments for file() and open() are: (filename, mode, buffering). How do you refer to the filename? Do you put it in quotes? Do you put in the file's full directory path? Or do file() and open() refer to the same directory as the one the script is in? Are the mode and buffering things always necessary arguments? For now, I just want to read/manipulate files, not write to them. What do file() and open() create? Do you need to set them equal to some variable? Is one better than the other? I want to create a list, where each list item is a line in the file. (The, my program would do stuff with the list.) ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Starting with wxPython
I'm not quite there yet, but I want to get into using GUIs in Python soon, and I plan to use wxPython to do so. What, do you think, is the best tutorial out there for wxPython? Also, what happens when you code for some GUI feature and run the script in your IDE, such as IDLE? Will the graphical features properly appear? ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] I want some help with arrays...
Why Python starts counting at [0] instead of at [1] is a whole other issue. :D array = [["0.0", "0.1"], ["1.0", "1.1"]] array[0[1]] seems right, although it isn't, because the index (0) and the subindex(1) are nested in 'array[0[1]]' much like the list and sublist that I'm "calling" from with the indexes. array[0][1] works instead? Gotcha. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] I want some help with arrays...
Ah, a simple concept. Good. :) I'm already familiar in working with lists. Here's a case of a simple two-dimensional array (the simplest possible), ran in the IDLE interpreter: >>> array = [["1.1", "1.2"], ["2.1", "2.2"]] >>> array[1[2]] Traceback (most recent call last): File "", line 1, in array[1[2]] TypeError: 'int' object is unsubscriptable >>> array[1] ['2.1', '2.2'] >>> second_half = array[1] >>> second_half[1] '2.2' When I nest the slices ( array[1[2]] ) I get that error message. When I define one variable as an index value of the array, and then index-value that, it works fine. What's the deal? ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] I want some help with arrays...
What is the best (only?) way to set up an array in Python. I've heard they can be quite good for certain types of data you need to organize... What IS the best reason(s) to be using an array? Apologies, if Python has something similar by a different name. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Checking/Debugging tools
Quoting Kent Johnson <[EMAIL PROTECTED]>: > Alan Gilfoy wrote: >> My programs often have long, detailed loops in them, and would like >>to, as I'm executing the loop, view what part of the loop Python >> is currently processing. >> >> Thus, if my program gets stuck in one part of the loop, I would see that. >> Thus, if one part of my loop is never triggered, I would see that. >> >> I could use, within my loop, print 'I am here, at part X of the >> loop', but I believe that would be far to clunky to put in every >> section of my program's loop(s). > > I'm not really sure what you expect this view to look like. I don't > know of any tool that will let you dynamically watch a program as it > executes. Some alternatives: > > - A debugger lets you step through the code and see how it behaves. > winpdb is a pretty nice GUI-based Python debugger and some Python > development tools have built-in debuggers. > http://www.digitalpeers.com/pythondebugger/ I got winpdb downloaded, but when I tried to run the script, it said I needed wxpython. I tried to go to the wxpytohn website, and it's evidently down right now. > > - If the program is stuck in a loop, pressing control-C will abort the > loop and give a stack trace showing you where it was. > > - The Python profiler will tell you (after the fact) how much time you > spend in each function. To see what part of a loop the program is in > you would have to break the loop up into functions. > http://docs.python.org/lib/profile.html My loop isn't broken into functions, just a truckload of if statements > > - A code coverage tool will tell you (after the fact) which lines of > the program were executed and which were not. (google python code > coverage) > Running that Google Search, I seem to be running into a lot of what is, to me, technical gobbeldygook. Can y'all help me choose a good code-coverage tool, and a good tutorial? > Kent Alan - End forwarded message - ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Repeating an action
How do you 'tell' Python to repeat a certain action X amount of times, and then stop. I could use a 'counter' (see below), but that seems kind of clunky. counter = 0 example = True while example: print "Do something" counter += 1 if counter == 100: example = False ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Loop-checking question
My programs often have long, detailed loops in them, and would like to, as I'm executing the loop, view what part of the loop Python is currently processing. Thus, if my program gets stuck in one part of the loop, I would see that. Thus, if one part of my loop is never triggered, I would see that. I could use, within my loop, print 'I am here, at part X of the loop', but I believe that would be far to clunky to put in every section of my program's loop(s). -- "Computers were the first God-Satan collaboration project." "Blind faith in bad leadership is not patriotism." "One of the most horrible features of war is that all the war-propaganda, all the screaming and lies and hatred, comes invariably from people who are not fighting."-George Orwell, _Homage to Catalonia ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Another string-manipulation question
Given a string, how would I?: 1. Make sure only the first letter string_name[0], is capitalized. This would involve using string_name.lower() to lowercase everything else, but how do I use .upper(), or some other method, to capitalize only the first character? 2. Make sure that there are no symbols (non-letter, non-number) in the string, and, if one is found, remove it. Pseudocode time, as to a potential approach- for each character in the string: if character not in "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ": remove it -- "Computers were the first God-Satan collaboration project." "Blind faith in bad leadership is not patriotism." "One of the most horrible features of war is that all the war-propaganda, all the screaming and lies and hatred, comes invariably from people who are not fighting."-George Orwell, _Homage to Catalonia ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Assembling multiple strings into one
I have a program producing a list of multiple strings. The amount of strings in the list varies. I want to assemble a string that is: list item 0 + space + list item 1 + space, and so on, going through every string in the list. -- "Computers were the first God-Satan collaboration project." "Blind faith in bad leadership is not patriotism." "One of the most horrible features of war is that all the war-propaganda, all the screaming and lies and hatred, comes invariably from people who are not fighting."-George Orwell, _Homage to Catalonia ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Working with error messages
I have a number-to-Roman numeral program that churns out ValueError messages with a few improper input cases: 1. not an integer 2. larger than 3999 3. smaller than 0 When I run the program via IDLE, and I give one of these improper inputs, the interpreter closes down the program and then displays the appropriate ValueError message. I would like the appropriate ValueError message to be displayed before the program shuts down, or at least a generic ValueError message. Is looking at my specific pieces of code necessary to help with this? I want this because if the program's being run as an application, the application window closes down as soon as the program closes, and the user doesn't get to see the message. [When I doubleclick on the .py file in Windows Explorer, it runs as a .exe, for example.] -- "Computers were the first God-Satan collaboration project." "Blind faith in bad leadership is not patriotism." "One of the most horrible features of war is that all the war-propaganda, all the screaming and lies and hatred, comes invariably from people who are not fighting."-George Orwell, _Homage to Catalonia ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] The IDLE subprocess
Often, when I am developing code, I get an error message saying that "IDLE's subprocess can't make connection" Sometimes this happends when I have IDLE open, and am about to hit F5 to run a program-in-process. Sometimes it happens when I opne up IDLE the first time. It's often fixed on restart of the program, not even restart of the computer. A big deal or not? And what does the subprocess do, anyway? -- "Computers were the first God-Satan collaboration project." "Blind faith in bad leadership is not patriotism." "One of the most horrible features of war is that all the war-propaganda, all the screaming and lies and hatred, comes invariably from people who are not fighting."-George Orwell, _Homage to Catalonia ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] A string-manipulation question
Awesome! (I was hoping it would be a 1-line solution. :) Thanks to batteries beign included, I don't necessarily need to worry about why and how .spilt() works. :) Quoting Bob Gailer <[EMAIL PROTECTED]>: > Alan Gilfoy wrote: >> Hi. I want to learn how to "break down" a string into its component >> words, and then process each word somehow. >> >> Is there a way in Python to separate a string into its component words. >> >> Like this: >> "I would like to convert an English string (sentence) into Pig Latin." >> >> The Pig Latin conversion I think I can handle already (if not, I'll >> cross that bridge when I come to it.) However, what I want help >> on is how to make each word of the string a separate value, or at >> least make it able to index the string by word, as opposed to the >> standard method of strings being indexed by character. >> > > "I would like to convert an English string (sentence) into Pig > Latin.".split() > yields: > ["I", "would", "like", "to", "convert", "an", "English", "string", > "(sentence)", "into", "Pig Latin."] > > > -- > Bob Gailer > 510-978-4454 ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] A string-manipulation question
Hi. I want to learn how to "break down" a string into its component words, and then process each word somehow. Is there a way in Python to separate a string into its component words. Like this: "I would like to convert an English string (sentence) into Pig Latin." The Pig Latin conversion I think I can handle already (if not, I'll cross that bridge when I come to it.) However, what I want help on is how to make each word of the string a separate value, or at least make it able to index the string by word, as opposed to the standard method of strings being indexed by character. -- "Computers were the first God-Satan collaboration project." "Blind faith in bad leadership is not patriotism." "One of the most horrible features of war is that all the war-propaganda, all the screaming and lies and hatred, comes invariably from people who are not fighting."-George Orwell, _Homage to Catalonia ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] String-manipulation question
#start of triple-letter processing block if len(roman_input) > 2 and roman_input[0] + roman_input[1] + roman_input[2] == "MMM": digital_result += 3000 roman_input = #something to remove those "M"'s from the string continue -- My question here boils down to, "Is there a way to remove certain characters from a string?" Here, I'm trying to set the variable roman_input (the string's name) equal to the string minus those characters, the 3 Ms. (being the first three characters of the string, they would be roman_input[0], roman_input[1], and roman_input[2].) Setting the (new) string equal to the (old) string minus those three characters will enable calculations on the string to keep running, because I have this piece of code, and similar pieces nested in a loop. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Roman Numeral - To - Digital Converter
Roman Numeral - To - Digital Converter So far, I'm coming along OK with the code that runs the conversions, assuming the user gives me a proper input. (A string of capital letters I, V, X, L, C, D, M) However, not every input someone gives the function is goign to be properly formatted like that. So: 1. How do I have my function "screen" an input string for characters that aren't I,V,X,L,C,D or M? 2. If any of the characters in the string are merely lowercase i,v,x,l,c,d, or m, how would I tell Python to capitalize those and go on with working the function? -- "Blind faith in bad leadership is not patriotism." "One of the most horrible features of war is that all the war-propaganda, all the screaming and lies and hatred, comes invariably from people who are not fighting."-George Orwell, _Homage to Catalonia ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Digital-to- Roman (pseudocode)
Quoting Bob Gailer <[EMAIL PROTECTED]>: >> >> Digital to Roman pseudocode: >> >> 1. if digital_input is greater than 1000: >> subtract 1000 from it and add "M" to string roman_result >> # How do you do that, add one character to the end of an existing string? >> > Start with an empty string: > > roman_result = "" > > To add a character at the end: > > roman_result += "M" # Python shorthand for roman_result = roman_result + "M" > roman_result + "M" would also work, right/ I'm just trying to save time on typing in the code, right > >> # also, how do I modify the digital_input variable (it's an integer) > digital_input -= 1000 is that somewhat like digital_result = digital result - int(1000)? >> several times through the conversion process? >> > You will be processing the input in a loop (while or for). running = True and while running is how I've tended to set (my pseudocode) > As you gain familiarity with Python you will develop ways to separate > data from logic. I might say more about this later, but right now I'm > about to drive north a bit. > I have already gained some familiary with separating data manipulation (data and logic, as a whole) from the code for the user interface, that's something that oen of my advisors has been big on. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Digital-to- Roman (pseudocode)
Quoting Bob Gailer <[EMAIL PROTECTED]>: > Make sure each step > is one simple operation. Walk thru the steps to verify that you have > them correct. Bob, your email did inspire me on how I would express the process in computer-processing terms. Here's how I'd break down the steps, using "pseudocode". I might also be askign how to convert each bit of pseudocode into actual code. (For both, I'm going to program in "exceptions" for numbers less than 0 or greater than 3999, which is MMMCMXCIX in Roman numerals. That is the highest number that can be expressed in Roman numerals using strings of no morer than 3 of the same letter (standard rule for Roman numerals), and using only the symbols I, V, X, L, C, D and M.) I know there are ways to express a Roman numeral for 5,000 and higher, but I'm goign to pgram those in later. Digital to Roman pseudocode: 1. if digital_input is greater than 1000: subtract 1000 from it and add "M" to string roman_result # How do you do that, add one character to the end of an existing string? # also, how do I modify the digital_input variable (it's an integer) several times through the conversion process? if digital_input is less than 1000: is it greater than 900? If so, subtract 900 from digital_input and add "CM" to string roman_reuslt is it less than 900? If it's less than 900, but greater than 500, subtract 500, and add "D" to the string. If it's less than 900, and less than 500, is it greater than 400? If so, subtract 400 from input and add "CD" to the string. If it isn't greater than 400, but greater than 100, subtract 100 from the input and add "C" to the result string. is it less than 100? If it is, but it's greater than 90, subtract 90 and add "XC" to the string. if it is less than 90, but greater than 50, subtract 50, and add "L" to the string. (and so on, down from 50 to 1) ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Roman to digital (pseudocode)
This, I heard, is more difficult than digital-to-Roman, since you have to "read" the subtractive cases, with a smaller numeral placed before a larger numeral, without simply adding all the numerals' values up I'm going to use a raw_input prompt to ask the user which Roman numeral he/she wants to convert. How do I "screen" for inputs that have characters besides "I", "V", "X", "L", "C", "D", or "M"? Second Python question: I know there's a way to "find out" the name of the first item in a list (ListName[0]), but is there a way to find out the first character of a string? Also, is there a way to "ask" Python what characters are before and after the character in the string that you're asking about? For example, usign the sample string "MCMXVII" (1917): How would you ask Python: "What's the 3rd character in this string?" (returns "M") "What's before that character?" (returns "C") Pseudocode time: If character Y is "M": and the character before character Y is "C", add 900 to digital_result and remove that "C" and that "M" from the string. #How would you do *that*? and the character before character Y is another "M", or if character Y is the first character in the string, add 1000 to digital_result and remove that "M" from the string. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] my program problem!
Hey! Glad to hear that using raw_input() at the end is the actual solution, not just a jury-rigged workaround. :) So sleep(10) would simply be a shorter snippet of code for that purpose? The \n thing might be handy if I was short on space, but I don't mind separate 'print' lines, I find that my code seems easier to read that way. (at least to me) I understand that having highly readable code is a ratehr desirable quality...:) -- "Blind faith in bad leadership is not patriotism." "One of the most horrible features of war is that all the war-propaganda, all the screaming and lies and hatred, comes invariably from people who are not fighting."-George Orwell, _Homage to Catalonia_ ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] program spontaneously closes...
Hello All.
I've been concocting some simple programs based on an online tutorial,
and I, of course, save a program as a .py file.
When running my program via IDLE, once I've cleaned out the bugs, it
works as I expect it to.
But I noticed something else:
Clicking directly on the file's icon has the program open in the
Windows command line program as a .exe file.
The command line program seems to work through my program OK, but the
command line program shuts down immediately after the program has run
through, as opposed to staying open in order to display the result. [I
noticed that if the command line program is not waiting for a resposne
to a prompt, it stays open.]
Relevant code block:
#rectangle stuff
length = int(raw_input("Please enter the length of your rectangle, as
a whole number : ")) #lets user input a number
width = int(raw_input("Please enter the width of your rectangle, as a
whole number : ")) #lets user input a number
area = length * width
print " "
print " "
print " "
print "the length is"
print length
print " "
print "the width is"
print width
print " "
print "So the area is"
print area
print " "
end = (raw_input("Type something, and press Enter, and the program
should shut down."))
#workaround
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Re: [Tutor] My number-guessing program
Yeah, that's what the wiki-based tutorial mentioned. In fact, Lee Harr (my community adviser) also suggested using a random number. Quoting Luke Paireepinart <[EMAIL PROTECTED]>: > Alan Gilfoy wrote: (the start of the code for my number-guessing thingamajig) >> >> else: >>print "The number-guessing loop is over." >> (some more code) My line: number = 3 Would I use 'number = random.randint()' in place of that, to have the relevant number be random? ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] senior project
I am a senior at the School Without Walls in Rochester, NY. As such, I get to do a senior project. I decided to work on computer programming, since that is sometihng that I certianly think can hold my interest throughout the school year. (despite my compute rinteresat, I've never done anything much more advanced than HTML, for some reason) One of my community advisers suggested I start with Python. (he also suggested this mailing list) So far, I've liked the http://swaroopch.info/text/Byte_of_Python:Main_Page tutorial, for basics. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] One of my 'baby step' programs
-code block-
number = 3
running = True
while running:
guess = int(raw_input("Please enter a number : ")) #lets user guess a number
if guess == number:
print "Yay, you got the right number, good for you. But you
don't get any prizes. Do I look like a walking ATM to you?"
running = False #this causes the guess-again loop to start.
elif guess < number:
print "No, my number is higher than that"
else:
print "No, my number is lower than that."
else:
print "The number-guessing loop is over."
print "Done."
-end code block-
Darnit, it's very simple, but I still like the fac tthat is does
something to user input.
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