Replacing spaces with hyphens

Question

I have the string "How are you". This string should become "How-are-you". It's possible with regex? How?

Answer 1

Another option is replace

$ python -m timeit 'a="How are you"; a.replace(" ", "-")'
1000000 loops, best of 3: 0.335 usec per loop
$ python -m timeit 'a="How are you"; "-".join(a.split())'
1000000 loops, best of 3: 0.589 usec per loop

Answer 2

Just use pythons built in replace method:

strs = "How are you"
new_str = strs.replace(" ","-")
print new_str // "How-are-you"

Answer 3

Why use a regex?

x =  "How are you"
print "-".join(x.split())

--output:--
How-are-you

Answer 4

Depending on your precise needs, there is many variation on that theme using regular expressions:

# To replace *the* space character only
>>> re.sub(' ', '-', "How are you");

# To replace any "blank" character (space, tab, ...):
>>> re.sub('\s', '-', "How are you");

# To replace any sequence of 1 or more "blank" character (space, tab, ...) by one hyphen:
>>> re.sub('\s+', '-', "How     are             you");

# To replace any sequence of 1 or more "space" by one hyphen:
>>> re.sub(' +', '-', "How     are             you");

Please note for "simple" substitution replace is probably more appropriate than using regular expression (those are really powerful, but requires a compilation phase before processing that could be expensive. Not sure this would really impact your program for such a simple case though... ;). Finally for the one special case or replacing sequences of spaces, nothing could probably beat x.join(str.split())...

Answer 5

As you asked, using regex:

>>> import re
>>> s = "How are you"
>>> print re.sub('\s', '-', s)
How-are-you