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Unfortunately, the example still contains duplicated information (and effort). I would do: words = ["zero", "one", "two", "three", "four", "five",

Unfortunately, the example still contains duplicated information (and effort). I would do: words = ["zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"] numbers = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] number_to_word = dict(zip(numbers, words)) word_to_number = dict(zip(words, numbers)) The rest, of course, can remain the same. I think adding this would also help to show how Python idioms like zip can help simplify code. That said, I still voted the submission up. I've seen several articles like this which point out how people use new languages in the same braindead way they used their old languages, yet I feel this one featured a very simple example with a paradigm that maps well to Python. EDIT: Whoops, I got distracted and didn't realize that I didn't finish reading the article. It turns out that the approach is modified later on to do something even better, but I'll leave you to check out the article for that.

kirubakaran 19y ago
Yes. Also, number_to_word dictionary is not needed as words[0] is already "zero"
- BrandonM 19y ago
  Good point. That idea was not mentioned in the article, and it would obviously take up less space and be a faster lookup.
mrtron 19y ago
numbers = range(10) is mucho easier than typing the numbers :) words = ["zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"] number_to_word = dict(zip(range(10), words)) word_to_number = dict(zip(words, range(10))) The last approach with lots of testing is good.
- BrandonM 19y ago
  Well, here's the approach that was settled on in the article: import string words = "zero one two three four five six seven eight nine".split() number_to_word = dict(zip(string.digits, words)) word_to_number = dict(zip(words, range(10))) I'm not sure why string.digits was used in the first zip but not the second. As kirubakaran pointed out, though, the number_to_word dictionary isn't even needed. The best approach, in my opinion, becomes: number_to_word = "zero one two three four five six seven eight nine".split() word_to_number = dict(zip(number_to_word, range(10)) This would serve to display several cool Python idioms: the simplicity of string splitting, the power of zip, the simplicity of producing a list of numbers, and the use of the accessor on different types of data structures. If memory recalls, none of those operations are that easy to do in Java.
  - dood 19y ago
    It can be made a little neater, show off a little more of Python and be more versatile by replacing range(10) with count() from the iterator module [http://docs.python.org/lib/itertools-functions.html http://docs.python.org/lib/itertools-functions.html] from itertools import count words = "zero one two three four five six seven eight nine".split() word_to_number = dict(zip(words, count())) [http://codepad.org/naCDzno7 http://codepad.org/naCDzno7]
    - BrandonM 19y ago
      I like itertools as much as the next programmer (although a large subset of it will be subsumed when Python3k switches to iterators on operations like map and zip), but I feel like using an imported module to (apparently) produce a list of numbers might actually give the wrong idea about Python. In several other languages, you can't even write to standard output without importing a module or five, whereas in Python, you can get a lot done without even touching the standard library (although you will likely want to rather quickly). Seeing an import statement at the top might give the Python newbie the idea that core Python doesn't have "basic" functionality. I think a good later lesson would be to explain how iterators and the standard library works and then revisit this code to make it look like your example, but in the beginning, I think range(10) would be simpler and would better serve the purpose of the lesson. Even in this case, xrange (at least in Python 2.x) is obviously the better choice, but introducing that complexity at this point doesn't gain much, in my opinion.
      - eru 19y ago
        Won't range behave like xrange soon anyway?
    - jacobolus 19y ago
      Or just: words = "zero one two three four five six seven eight nine ten".split() word_to_number = dict((j,i) for i,j in enumerate(words))
brlewis 19y ago
Schemers who want to borrow the zip idiom can do this: (define (zip . lists) (apply map list lists))
hobbs 19y ago
Real programmers can write Fortran in any language.

kirubakaran 19y ago

Yes. Also, number_to_word dictionary is not needed as words[0] is already "zero"

BrandonM 19y ago
Good point. That idea was not mentioned in the article, and it would obviously take up less space and be a faster lookup.

mrtron 19y ago

numbers = range(10) is mucho easier than typing the numbers :) words = ["zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"] number_to_word = dict(zip(range(10), words)) word_to_number = dict(zip(words, range(10))) The last approach with lots of testing is good.

BrandonM 19y ago
Well, here's the approach that was settled on in the article: import string words = "zero one two three four five six seven eight nine".split() number_to_word = dict(zip(string.digits, words)) word_to_number = dict(zip(words, range(10))) I'm not sure why string.digits was used in the first zip but not the second. As kirubakaran pointed out, though, the number_to_word dictionary isn't even needed. The best approach, in my opinion, becomes: number_to_word = "zero one two three four five six seven eight nine".split() word_to_number = dict(zip(number_to_word, range(10)) This would serve to display several cool Python idioms: the simplicity of string splitting, the power of zip, the simplicity of producing a list of numbers, and the use of the accessor on different types of data structures. If memory recalls, none of those operations are that easy to do in Java.
- dood 19y ago
  It can be made a little neater, show off a little more of Python and be more versatile by replacing range(10) with count() from the iterator module [http://docs.python.org/lib/itertools-functions.html http://docs.python.org/lib/itertools-functions.html] from itertools import count words = "zero one two three four five six seven eight nine".split() word_to_number = dict(zip(words, count())) [http://codepad.org/naCDzno7 http://codepad.org/naCDzno7]
  - BrandonM 19y ago
    I like itertools as much as the next programmer (although a large subset of it will be subsumed when Python3k switches to iterators on operations like map and zip), but I feel like using an imported module to (apparently) produce a list of numbers might actually give the wrong idea about Python. In several other languages, you can't even write to standard output without importing a module or five, whereas in Python, you can get a lot done without even touching the standard library (although you will likely want to rather quickly). Seeing an import statement at the top might give the Python newbie the idea that core Python doesn't have "basic" functionality. I think a good later lesson would be to explain how iterators and the standard library works and then revisit this code to make it look like your example, but in the beginning, I think range(10) would be simpler and would better serve the purpose of the lesson. Even in this case, xrange (at least in Python 2.x) is obviously the better choice, but introducing that complexity at this point doesn't gain much, in my opinion.
    - eru 19y ago
      Won't range behave like xrange soon anyway?
  - jacobolus 19y ago
    Or just: words = "zero one two three four five six seven eight nine ten".split() word_to_number = dict((j,i) for i,j in enumerate(words))

brlewis 19y ago

Schemers who want to borrow the zip idiom can do this: (define (zip . lists) (apply map list lists))

hobbs 19y ago

Real programmers can write Fortran in any language.