在python中逐步浏览字典中的项目

Question

I have a dictionary like so:

{'AAAGGG': ['AGAGAGAA', 'AGAGAGAG'], 'AAAGGC': ['AGAGAGAG']})

I want to step through each key and then step through the chars of its corresponding values. So something like this:

for key in myDict:
    for eachValue in key:
        for char in eachValue:
            do something

Hopefully there is an easy way of doing this.

Answer 1

Python Tutorial: Looping Techniques

When you have the key, use the key to look up the value. Don't iterate through the key.

for key in myDict:
    for eachValue in myDict[key]:
        for char in eachValue:
            do something

More efficiently, iterate through the items and avoid the extra lookup:

for key, value in myDict.items():
    for eachValue in value:
        for char in eachValue:
            do something

Answer 2

This should do it:

my_dict = {'AAAGGG': ['AGAGAGAA', 'AGAGAGAG'], 'AAAGGC': ['AGAGAGAG']})

for parent_value in my_dict.values():
    for sub_value in parent_value:
        for char in sub_value:
            do_something(char)

Answer 3

You're looking for chain.from_iterable :

from itertools import chain
print list(chain.from_iterable({'long_key': ["abc", "cdef"], 'another_key':['ZYC', 'hgt']}.keys()))
#  ['a', 'n', 'o', 't', 'h', 'e', 'r', '_', 'k', 'e', 'y', 'l', 'o', 'n', 'g', '_', 'k', 'e', 'y']