I have a list of objects appended from a mysql database and contain spaces. I wish to remove the spaces such as below, but the code im using doesnt work?
hello = ['999 ',' 666 '] k =  for i in hello: str(i).replace(' ','') k.append(i) print k
Strings in Python are immutable (meaning that their data cannot be modified) so the replace method doesn't modify the string - it returns a new string. You could fix your code as follows:
for i in hello: j = i.replace(' ','') k.append(j)
However a better way to achieve your aim is to use a list comprehension. For example the following code removes leading and trailing spaces from every string in the list using
hello = [x.strip(' ') for x in hello]
[num.strip() for num in hello] is the fastest.
>>> import timeit >>> hello = ['999 ',' 666 '] >>> t1 = lambda: map(str.strip, hello) >>> timeit.timeit(t1) 1.825870468015296 >>> t2 = lambda: list(map(str.strip, hello)) >>> timeit.timeit(t2) 2.2825958750515269 >>> t3 = lambda: [num.strip() for num in hello] >>> timeit.timeit(t3) 1.4320335103944899 >>> t4 = lambda: [num.replace(' ', '') for num in hello] >>> timeit.timeit(t4) 1.7670568718943969