N
Nick Mellor
Hi,
I came across itertools.dropwhile only today, then shortly afterwards found Raymond Hettinger wondering, in 2007, whether to drop [sic] dropwhile and takewhile from the itertools module.
Fate of itertools.dropwhile() and itertools.takewhile() - Python
bytes.com
http://bit.ly/Vi2PqP
Almost nobody else of the 18 respondents seemed to be using them.
And then 2 hours later, a use case came along. I think. Anyone have any better solutions?
I have a file full of things like this:
"CAPSICUM RED fresh from Queensland"
Product names (all caps, at start of string) and descriptions (mixed case, to end of string) all muddled up in the same field. And I need to split them into two fields. Note that if the text had said:
"CAPSICUM RED fresh from QLD"
I would want QLD in the description, not shunted forwards and put in the product name. So (uncontrived) list comprehensions and regex's are out.
I want to split the above into:
("CAPSICUM RED", "fresh from QLD")
Enter dropwhile and takewhile. 6 lines later:
from itertools import takewhile, dropwhile
def split_product_itertools(s):
words = s.split()
allcaps = lambda word: word == word.upper()
product, description = takewhile(allcaps, words), dropwhile(allcaps, words)
return " ".join(product), " ".join(description)
When I tried to refactor this code to use while or for loops, I couldn't find any way that felt shorter or more pythonic:
(9 lines: using for)
def split_product_1(s):
words = s.split()
product = []
for word in words:
if word == word.upper():
product.append(word)
else:
break
return " ".join(product), " ".join(words[len(product):])
(12 lines: using while)
def split_product_2(s):
words = s.split()
i = 0
product = []
while 1:
word = words
if word == word.upper():
product.append(word)
i += 1
else:
break
return " ".join(product), " ".join(words[i:])
Any thoughts?
Nick
I came across itertools.dropwhile only today, then shortly afterwards found Raymond Hettinger wondering, in 2007, whether to drop [sic] dropwhile and takewhile from the itertools module.
Fate of itertools.dropwhile() and itertools.takewhile() - Python
bytes.com
http://bit.ly/Vi2PqP
Almost nobody else of the 18 respondents seemed to be using them.
And then 2 hours later, a use case came along. I think. Anyone have any better solutions?
I have a file full of things like this:
"CAPSICUM RED fresh from Queensland"
Product names (all caps, at start of string) and descriptions (mixed case, to end of string) all muddled up in the same field. And I need to split them into two fields. Note that if the text had said:
"CAPSICUM RED fresh from QLD"
I would want QLD in the description, not shunted forwards and put in the product name. So (uncontrived) list comprehensions and regex's are out.
I want to split the above into:
("CAPSICUM RED", "fresh from QLD")
Enter dropwhile and takewhile. 6 lines later:
from itertools import takewhile, dropwhile
def split_product_itertools(s):
words = s.split()
allcaps = lambda word: word == word.upper()
product, description = takewhile(allcaps, words), dropwhile(allcaps, words)
return " ".join(product), " ".join(description)
When I tried to refactor this code to use while or for loops, I couldn't find any way that felt shorter or more pythonic:
(9 lines: using for)
def split_product_1(s):
words = s.split()
product = []
for word in words:
if word == word.upper():
product.append(word)
else:
break
return " ".join(product), " ".join(words[len(product):])
(12 lines: using while)
def split_product_2(s):
words = s.split()
i = 0
product = []
while 1:
word = words
if word == word.upper():
product.append(word)
i += 1
else:
break
return " ".join(product), " ".join(words[i:])
Any thoughts?
Nick