On 07/06/2013 05:38 PM, Jim Mooney wrote:
I reworked my numbers_to_name program so I can actually follow the logic.
Since I think the best way to learn is to follow something through to
completion, I'll put it online so I learn how to do that. But naturally,
lest I look dumb, I'd appreciate criticism, improvements of bad form,
or if
anyone can break it, let me know ;') . Seems to work with a bit of random
testing, but ya never know. If you did, Msoft wouldn't be putting out
those
updates all the time. Works with Py 27 or 33, but that brings up a
question: I think most of my programs work with both if I don't do
anything
exotic, except for input(), which is the fly in the ointment. Instead of
using the routine below, could I redefine input() to use the routine,
or it
that a bad idea?
I have a feeling the leftpad routine could be simplified, but it isn't
coming to me.
General comments:
1) several lines wrapped in the newreader, so I had to paste things
together. Presumably this won't happen whereever you put it online, but
you should make sure and check after uploading it to make sure no such
problems were introduced.
Also, instead of using the backslash line-continuation character, I
generally try to use the syntax of the language instead. So if you have
a quote which won't fit on one line, but you don't want embedded
newlines in it either, you can use the implicit concatenation of
adjacent literals. Frequently you have to put parens around the whole
thing to make sure the compiler sees it as one line. But I think it's
usually more readable that way.
First example: the prompt in the input/raw_input lines.
# Using C:\Python33\python.exe on Win 7 in c:\python33\jimprogs - not
Windows-specific
# Also works with python 2.7
You always take the data in by input/raw_input. Why not permit a value
on the command line? And even more important, you're mixing
input/output with algorithm here.
import sys
# Data
ones = {'1': 'one', '2': 'two', '3': 'three', '4': 'four', '5': 'five',
'6': 'six',
'7': 'seven', '8': 'eight', '9': 'nine'}
tens = {'2': 'twenty', '3': 'thirty', '4': 'forty', '5': 'fifty', '6':
'sixty',
'7': 'seventy', '8': 'eighty', '9': 'ninety'}
doubles = {'0': 'ten', '1': 'eleven', '2': 'twelve', '3': 'thirteen',
'4':
'fourteen',
'5': 'fifteen', '6': 'sixteen', '7': 'seventeen', '8': 'eighteen', '9':
'nineteen'}
powers_of_1000 = (' thousand', ' million', ' billion', ' trillion',
' quadrillion', ' quintillion', ' sextillion', ' septillion', '
octillion',
' nonillion', ' decillion')
'''add these later, and also option for dollars-and-cents ending.
'vigintillion', 'novemdecillion', 'octodecillion', 'septendecillion',
'sexdecillion', 'quindecillion', 'quattuordecillion', 'tredecillion',
'duodecillion', 'undecillion',
'decillion', 'nonillion'
Those last two you've already implemented
'''
# Functions
def make_triplets_from_input():
'''Enter a positive integer. A list of triplets in the same order
will
be returned.
Raise ValueError to loop on non-integer input, or return 'zero'
trigger-value of
'xxx' if all zeroes are entered. If input is okay, strip leading
zeroes, then
zero-pad leftmost triplet to three characters, so all slices are
triplets. Adjust
input for different Python versions.'''
while True:
try:
if sys.version[0:3] == '2.7':
I'd do the version checking in initialization code, not here. And I'd
do it by redefining input to do what it does in 3.3
numbers_str = original = raw_input('Enter a positive
integer, space \
separated if desired.')
elif sys.version[0:3] == '3.3':
numbers_str = original = input('Enter a positive
integer,
space \
separated if desired.')
Note: you explicitly support zero, so this should say non-negative,
rather than positive.
I'm not sure why you support spaces between the digits, and not commas,
but no biggie. BTW, you also support other white space, like tabs.
else:
print('Python versions 2.7 and 3.3 only supported')
sys.exit()
numbers_str = ''.join(numbers_str.split())
if numbers_str == '' or numbers_str == ' ': raise ValueError
numbers_int = int(numbers_str)
if numbers_int == 0:
print('Zero')
sys.exit()
This is just weird. You're in the middle of an input routine, and you
just print something and exit the code??
numbers_str = str(numbers_int)
if len(numbers_str) > 36: raise ArithmeticError
break
except KeyboardInterrupt:
print('Program cancelled by user')
sys.exit()
except ValueError as err:
print(original, "is not an integer.")
continue
except ArithmeticError as err:
print(original, "is too big.\n999...decillion is max:
10**37-1
or 36 chars \
or 12 groups of 3 chars")
leftpad = len(numbers_str) % 3 # zero-pad left, so we get all
3-character triplets
if leftpad == 0: leftpad = ''
elif leftpad == 2: leftpad = '0'
else: leftpad = '00'
Instead of these four lines, how about:
leftpad = "0" * (-i)%3
numbers_str = leftpad + numbers_str
triplets = [numbers_str[x:x+3] for x in range(0,len(numbers_str),3)]
return (triplets, len(triplets))
Seems a little silly to make this a tuple, when the second value is
trivially figured from the first. You could just have the second
function take a single list argument and take its len() for itself.
And even then, I'd recommend using a slice when calling it instead of
passing it a number. Just one more bug lurking in the wings.
def numbers_to_name(triplets, triplen):
'''Create a name from each triplet and append the power of ten'''
triplen -= 2
number_name = ''
for triplet in triplets:
triplet_name = ''
first, second, third, last_two = (triplet[0], triplet[1],
triplet[2], triplet[1:])
if triplet == '000':
triplen -= 1
continue
if first > '0':
if last_two == '00': # special case - snip extra space
separator
triplet_name += ones.get(first) + ' hundred'
else:
triplet_name += ones.get(first) + ' hundred '
if second == '0':
if third > '0':
triplet_name += ones.get(third)
elif second == '1':
triplet_name += doubles.get(third)
elif second > '1':
triplet_name += tens.get(second)
if third > '0':
triplet_name += '-' + ones.get(third)
number_name += triplet_name
if triplen > -1:
number_name += powers_of_1000[triplen] + ', '
triplen -= 1
if number_name[-2] == ',':
number_name = number_name[0:-2] # special case - snip extraneous
ending comma
return number_name
# Main Program - turn numeric input into number-names
triplets, triplen = make_triplets_from_input()
print(numbers_to_name(triplets, triplen))
If you included the usual if __name__ == test around those two lines,
you'd be able to use this same file as an importable module.
You should have four functions, not two:
1) parse argv
2) get input from user
3) turn string into list ( make_triplets_from_input)
4) turn list into string, ready to print (numbers_to_name)
and then the top-level code does something like:
if __name__ == "__main__":
if len(argv) == 2:
raw = parseargv()
elif len(argv) == 1:
raw = getinputfromuser()
else:
someerrormessage
exit
triplets = make_triplets_from_input(raw)
print(numbers_to_name(triplets))
