Question

I am working with Google Python class exercises where I am getting this issue –

def front_x(words):
  # +++your code here+++
  list = []
  for i,s in enumerate(words):
    print i,s
    if s[0] == 'x':
        list.append(words.pop(i))
  return list

print front_x(['bbb','ccc','axx','xzz','xaa'])

my loop is only iterating from 0 to 3, so print i,s is giving me values till ‘xzz’.Please point where I am wrong.

Answer 1

Don’t modify something as you’re iterating over it. words.pop(i) modifies words, which you’re iterating over via enumerate().

I’d suggest looking at list comprehensions for accomplishing your apparent goal.