Re: [Tutor] First Try 1.2
Hi John,
Its developing nicely so I'll add some more style issue comments :-)
import random
# store the /home/mutt/lotto.txt in f
f = file('/home/mutt/lotto.txt','w')
# create or replace lotto.txt in my home directory
f.write('Here are your numbers:\n\n')
I'd move the middle comment up with the one above.
Think of a block of comments commenting on a paragraph of
code, rather than dealing in single lines:
# store the /home/mutt/lotto.txt in f
# create or replace lotto.txt in my home directory
f = file('/home/mutt/lotto.txt','w')
f.write('Here are your numbers:\n\n')
Now the code is easier sepsarated from the comment.
BUT, is the comment really needed, after all the explicit pathname
shows whgere it is going and the variable tells us where we are storing it.
How much of:
f = file('/home/mutt/lotto.txt','w')
f.write('Here are your numbers:\n\n')
will be hard to understand if you come back in a few months?
Comments are best used to explain the *why* of code and let good
variable names and structure describe the how. A concept often
called Self documenting code
# user input for number of games to generate
how_many_games = int(raw_input('How many games you would like generated?
'))
# user input for number of balls (to allow different lotto games)
number_of_balls = int(raw_input('\nHow many balls are in the lotto you
wish to play? '))
# user input for how many numbers per game (to allow systems entries)
how_many_numbers = int(raw_input('\nHow many numbers you would like per
game? '))
# check if there is a power ball
chk_pwrball = raw_input('Is there a power ball? (y/n) ')
how_many_games = int(raw_input('How many games you would like generated?
'))
number_of_balls = int(raw_input('\nHow many balls are in the lotto you
wish to play? '))
how_many_numbers = int(raw_input('\nHow many numbers you would like per
game? '))
chk_pwrball = raw_input('Is there a power ball? (y/n) ')
Again comparing these two do the comments add much more information than
the variable names do? And by removing them the code itself becomesa much
more obvious and readable.
print '\n\nHere are your numbers : \n'
# loop for the number of games selected by user
for game in range(1, how_many_games + 1):
# generate 6 random numbers between 1 and 45 inclusive then sort them
lotto_numbers = random.sample(range(1,number_of_balls + 1),
how_many_numbers)
lotto_numbers.sort()
if chk_pwrball == 'n':
# Right justified in 3 character width then a tab (\t) then a blank
line (\n)
print '%3s\t%s\n' % (game, lotto_numbers)
# write the numbers to lotto.txt
save_numbers = 'Game: %3s\t%3s\n' % (game, lotto_numbers)
f.write(save_numbers)
The commenting in this section is better spaced but again mostly just
says what the code does. The comment explaining the string format is
probably the most valid comment in the program, it describes what the
format is trying to accomplish which is valid since format strings are
not self evident.
if chk_pwrball == 'y':
pwrball = random.sample(range(1,number_of_balls +1), 1)
print '%3s\t%s \tPower Ball: %s\n' % (game, lotto_numbers,
pwrball)
save_numbers = 'Game: %3s\t%s \tPower Ball: %s\n' % (game,
lotto_numbers, pwrball)
f.write(save_numbers)
print '\nHope you win!'
f.write('\nHope you win!')
f.close()
And interesting that you (coprrectly) chose not to comment this sectoon at
all
Don't take these comments too personally but it is just a classic case of
how
you have improved the code clarity to the point where the comments, which
were originally necessary, are now superfluous! This is a common mistake
for beginners so I thought I'd take the opportunity to highlight the issue:
Comments are useful but clearly written code is much better
Alan G
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Re: [Tutor] First Try 1.2
G'day,
Added a power ball option to the lotto program today. The program does way
more then I ever intended when I started it so I'll try a new project. Maybe
I'll come back to it when I try out Tkinter and try to give it a GUI.
Anywayhere's my latest effort.
import random
# store the /home/mutt/lotto.txt in f
f = file('/home/mutt/lotto.txt','w')
# create or replace lotto.txt in my home directory
f.write('Here are your numbers:\n\n')
# user input for number of games to generate
how_many_games = int(raw_input('How many games you would like generated? '))
# user input for number of balls (to allow different lotto games)
number_of_balls = int(raw_input('\nHow many balls are in the lotto you wish
to play? '))
# user input for how many numbers per game (to allow systems entries)
how_many_numbers = int(raw_input('\nHow many numbers you would like per
game? '))
# check if there is a power ball
chk_pwrball = raw_input('Is there a power ball? (y/n) ')
print '\n\nHere are your numbers : \n'
# loop for the number of games selected by user
for game in range(1, how_many_games + 1):
# generate 6 random numbers between 1 and 45 inclusive then sort them
lotto_numbers = random.sample(range(1,number_of_balls + 1),
how_many_numbers)
lotto_numbers.sort()
if chk_pwrball == 'n':
# Right justified in 3 character width then a tab (\t) then a blank
line (\n)
print '%3s\t%s\n' % (game, lotto_numbers)
# write the numbers to lotto.txt
save_numbers = 'Game: %3s\t%3s\n' % (game, lotto_numbers)
f.write(save_numbers)
if chk_pwrball == 'y':
pwrball = random.sample(range(1,number_of_balls +1), 1)
print '%3s\t%s \tPower Ball: %s\n' % (game, lotto_numbers,
pwrball)
save_numbers = 'Game: %3s\t%s \tPower Ball: %s\n' % (game,
lotto_numbers, pwrball)
f.write(save_numbers)
print '\nHope you win!'
f.write('\nHope you win!')
f.close()
John
_
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Re: [Tutor] First Try 1.2
John Connors wrote:
import random
# store the /home/mutt/lotto.txt in f
f = file('/home/mutt/lotto.txt','w')
# create or replace lotto.txt in my home directory
f.write('Here are your numbers:\n\n')
The comments don't really add anything to the program. Comments that
restate exactly what the code is doing are not that helpful. The code
should be clear by itself. As a beginner they may seem like a helpful
crutch but you will get better at reading the code.
For example,
how_many_games = int(raw_input('How many games you would like generated? '))
is well-written and expressive. With the helpful variable name and the
input prompt it's pretty easy to figure out what it does. Adding the comment
# user input for number of games to generate
actually obscures the code without adding to its comprehensibility.
A better choice might be to have one comment for the whole block of user
input code, something like
# Get required user input
Good comments describe the code at a higher level than the code itself,
or explain tricky bits. Comments that give a blow-by-blow account of the
code just get in the way.
I will often break my code into small chunks with a comment before each
chunk that says what it does. Then it is very easy to skim the code and
skip sections I'm not interested in.
# user input for number of games to generate
how_many_games = int(raw_input('How many games you would like generated? '))
# user input for number of balls (to allow different lotto games)
number_of_balls = int(raw_input('\nHow many balls are in the lotto you wish
to play? '))
# user input for how many numbers per game (to allow systems entries)
how_many_numbers = int(raw_input('\nHow many numbers you would like per
game? '))
# check if there is a power ball
chk_pwrball = raw_input('Is there a power ball? (y/n) ')
Here is another reason why it is a bad idea to just describe the code in
the comments - often the code changes and the comment doesn't. Now you
have an inaccurate comment which is worse than no comment at all.
# generate 6 random numbers between 1 and 45 inclusive then sort them
lotto_numbers = random.sample(range(1,number_of_balls + 1),
how_many_numbers)
print '\nHope you win!'
Good luck!
Kent
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[Tutor] First Try 1.2
G'day :)
I've added a little more to the program. It now sorts the game numbers from
lowest to highest which makes filling out the tickets a lot easier, I've
been putting off doing this because I wasn't sure how to go about it but
once I started looking I found python does it all for me with .sort()
Also added some extra user input so different types of lotto games can be
played.
Found a glaring bug...the program didn't pick the winning numbers for me and
I'm now $6 poorer! g
Next on the to do list is add an option for a power ball, I actually did
this tonight but I had 'if' statements all over the place. Which made the
code unreadable so I'm going to work on a different way of doing it.
I hope posting my efforts in here is ok. I learnt a lot after posting the
first version of it but if I'm doing the wrong thing please tell me and I'll
desist.
import random
# create or replace lotto.txt in my home directory
file('/home/mutt/lotto.txt','w').write('Here are your numbers:\n\n')
# user input for number of games to generate
how_many_games = int(raw_input('How many games you would like generated? '))
# user input for number of balls (to allow different lotto games)
number_of_balls = int(raw_input('\nHow many balls are in the lotto you wish
to play? '))
# user input for how many numbers per game (to allow systems entries)
how_many_numbers = int(raw_input('\nHow many numbers you would like per
game? '))
print '\n\nHere are your numbers : \n'
# loop for the number of games selected by user
for game in range(1, how_many_games + 1):
# generate 6 random numbers between 1 and 45 inclusive
lotto_numbers = random.sample(xrange(1,number_of_balls + 1),
how_many_numbers)
lotto_numbers.sort()
# Right justified in 3 character width then a tab (\t) then a blank line
(\n)
print '%3s\t%s\n' % (game, lotto_numbers)
# append the numbers to lotto.txt
file('/home/mutt/lotto.txt','a').write('Game: ')
file('/home/mutt/lotto.txt','a').write(str(game))
file('/home/mutt/lotto.txt','a').write('')
file('/home/mutt/lotto.txt','a').write(str(lotto_numbers))
file('/home/mutt/lotto.txt','a').write('\n')
print '\nHope you win!'
file('/home/mutt/lotto.txt','a').write('\n\nHope you win!')
John
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