iter_chain.py

gistfile1.py

from itertools import imap                                                                                                       
def foo(x): return iter(x) # function which returns an iter                                                                      
bar = ["bar", "baz"]                                                                                                             
list(foo("bar"))                                                                                                                 
#[Out]# ['b', 'a', 'r']                                                                                                          
baz = iter(bar) # iterator of inputs                                                                                             
qu = (item for sublist in imap(foo, baz) for item in sublist)                                                                    
list(qu) # demonstration of chaining things together                                                                             
#[Out]# ['b', 'a', 'r', 'b', 'a', 'z'] 

# let's define a generic interface for such compositions
# bind_gen:: (a -> [b]) -> [a] -> [b], where [] = iter/generator
# note the similarity to qu above. bind_gen should be a utility function
def bind_gen(f, xs): (y for ys in imap(f, xs) for y in ys)