CODEWITHSUNDEEP
pythonstringintmultiprocessingtypeerror
Wahab Ehsan
Wahab Ehsan

Reputation: 9

TypeError: string indices must be integers for Multiprocessing Pool

I'm trying to figure out how to use multiprocessing, but having an issue with the following code. When running the pool_testing() function I get a TypeError. I tried changing pool = multiprocessing.Pool() to pool = multiprocessing.Pool(processes=n), but same error. Can anybody please help? 

import multiprocessing  

profile = [{u'firstName': u'Karen', u'age': 20},
           {u'firstName': u'Jon', u'age': 25}] 

def testing(profile):
    for i in profile:
        print ("Hey " + str(i["firstName"]) + "!")

def pool_testing():
    pool = multiprocessing.Pool()
    pool.map(testing, profile)

pool_testing()

Traceback:

File "/System/.../multiprocessing/pool.py", line 567, in get
    raise self._value
TypeError: string indices must be integers

Upvotes: 0

Views: 887

Answers (1)

101
101

Reputation: 8999

pool.map automatically maps each item of the iterable argument to the function, so you don't need to do it manually (for i in profile) - profile is already the item your interested in. The relevant line in the function description:

This method chops the iterable into a number of chunks which it submits to the process pool as separate tasks.

So, in your case your testing function would look like:

def testing(profile):
    print "Hey " + str(profile["firstName"]) + "!"

Upvotes: 1

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