module not recognizing index variable

Question

I'd like to return the help text for each function in a given module (for example os). The code below (Code Block A) returned the following error:

AttributeError: module 'os' has no attribute 'i'

#Code block A

import os
for i in dir(os):
    print (help(os.i))

If instead I run the code below (Code Block B), the function name in the ith position is returned at each step in the for loop.

#Code block B

for i in dir(os):
    print (i)

Q1. Why is the index variable i recognized as "i" in Code Block A "help(os.i)", but not in Code Block B "print(i)?

Q2. Is there a way to call each item in an iterable as a function (something akin to Code Block A) for a given module?

Thanks in advance for any insights or recommendations.

I don't agree that the question as originally posted was a duplicate. Though this may be due to my inexperience dealing directly with classes and programming in this way. The answer provided by jk622 is helpful. — noob99, Mar 14 '18 at 17:02
Welcome to the community. If an answer has helped you solve your problem, you should accept it. See [How does accepting an answer work.](https://meta.stackexchange.com/a/5235) — Mr. Kelsey, Mar 14 '18 at 20:51

Mr. Kelsey · Accepted Answer · 2018-03-14T14:59:48.033

There are a handful of occasions in python where the i variable that would otherwise represent an iterable, is instead treated as the string literal "i". In those cases, it is best to build a string by adding the iterable (represented by i) cast as a string to whatever else you were trying to add it to. Then you just feed the entire string into the function as needed.

In your particular case:

for i in dir(os):
    s = "os." + str(i)
    print(help(s))

module not recognizing index variable

1 Answers1