Add `item` for Tensor

[alewis]

Tensor should support the numpy-like function item, which converts a size-1 Tensor into a Python scalar.

[Sanchayan-Bhowal]

May i work on this issue?

[alewis]

Sure, sounds great!

[Sanchayan-Bhowal]

Actually I am new to GitHub. I have forked the issue and cloned it to my pc. Can u please guide me how to edit the code?

[mganahl]

Hey @Sanchayan-Bhowal, thanks for your contribution!

The workflow is as follows:

1. create a fork of the TensorNetwork repository
2. locally clone the fork to your computer:
   • $ git clone <your fork>
3. create a new branch for your PR: $ git checkout -b <my PR branch> master
4. fetch latest changes:
   • $ git fetch upstream
   • $ git merge upstream/master
5. add your changes to the code
6. commit and publish your changes:
   • $ git commit -a (commits all changes in a single commit, usually not ideal)
   • $ git push
7. on the gitub page of your fork, select Pull Request at the top, and submit a new PR

[Sanchayan-Bhowal]

@mganahl Thank you so much I will try to fix this issue as soon as possible

[Sanchayan-Bhowal]

@alewis I have generated a pull request and added a function please check it out