Adding elements to python generators

Question

Is it possible to append elements to a python generator?

I\'m currently trying to get all images from a set of disorganized folders and write them to a new directory

Answer 1

You are looking for itertools.chain. It will combine multiple iterables into a single one, like this:

>>> import itertools 
>>> for i in itertools.chain([1,2,3], [4,5,6]):
...     print(i)
... 
1
2
3
4
5
6

Answer 2

Like this.

def threeGens( i, j, k ):
    for x in range(i):
       yield x
    for x in range(j):
       yield x
    for x in range(k):
       yield x

Works well.

Answer 3

This should do it, where directories is your list of directories:

import os
import itertools

generators = [os.walk(d) for d in directories]
for root, dirs, files in itertools.chain(*generators):
    print root, dirs, files

Answer 4

def files_gen(topdir='.'):
    for root, dirs, files in os.walk(topdir):
        # ... do some stuff with files
        for f in files:
            yield os.path.join(root, f)
        # ... do other stuff

for f in files_gen():
    print f