Python dictionary == operator

Its interesting to note that python dictionaries support the == operator

References:

• https://stackoverflow.com/a/5635309
• https://stackoverflow.com/questions/17217225/what-does-the-operator-actually-do-on-a-python-dictionary
• https://www.laurentluce.com/posts/python-dictionary-implementation/
  • This is a nice read on Python’s dictionary implementation using hash tables
• https://hg.python.org/cpython/file/6f535c725b27/Objects/dictobject.c#l1839

Advertisements

TensorFlow – save, restore, freeze models

It can be quite tricky getting around to deploying TF models –

In fact there are multiple ways to save/load TF models, with each serving a slightly different purpose / use-case.

• simple_save
• saver
• estimator
• keras
• tflite

 

References:

• https://blog.metaflow.fr/tensorflow-how-to-freeze-a-model-and-serve-it-with-a-python-api-d4f3596b3adc
• https://gist.github.com/omimo/5d393ed5b64d2ca0c591e4da04af6009

Code:

• TensorFlow8_cifar.py
• TensorFlow8_cifar_load.py
• freeze.py

 

Consistent Hashing

References:

• https://stackoverflow.com/questions/144360/simple-basic-explanation-of-a-distributed-hash-table-dht
• http://michaelnielsen.org/blog/consistent-hashing/
• http://michaelnielsen.org/blog/lecture-course-the-google-technology-stack/
  • this is wonderful reading on Google’s technology stack!

 

Interfaces in Python : DuckTyping + ABCs

References:

• http://masnun.rocks/2017/04/15/interfaces-in-python-protocols-and-abcs/

Code:

 

Union-Find

The Union Find problem leads to an understanding of some very interesting data structures.

References:

• https://www.coursera.org/learn/algorithms-part1/home/welcome
• https://vancexu.github.io/2015/07/21/intro-to-union-find-data-structure-exercise.html
• https://jznotebook.com/2014/02/15/algorithms-part-i-social-network-connectivity-with-union-find/

Python sorted, itemgetter, stdin

I find it interesting how implementing a simple algorithm can teach you so many new things.

I was recently implementing the fractional knapsack problem

The interesting was – during implementation I got to learn some interesting things about Python.

• sorted
  • http://www.dr-chuck.com/csev-blog/2010/01/fun-python-syntax-operator-itemgetter-sorted-and-lambda-functions-oh-my/
  • https://algocoding.wordpress.com/2015/04/14/how-to-sort-a-list-of-tuples-in-python-3-4/
    • This link is actually quite useful!
• items, iteritems
  • https://stackoverflow.com/questions/10458437/what-is-the-difference-between-dict-items-and-dict-iteritems
• itemgetter
  • https://stackoverflow.com/questions/15371691/how-to-sort-a-dictionary-by-value-desc-then-by-key-asc
    • cool trick to sort by combination of ascending and descending
• sys.stdin
  • EOF literal for Windows is Control+Z  (not Control+D)

 

Code:

• fractional_knapsack.py

 

git submodule

There are some interesting articles out there about git submodules

Tips:

• cd into the submodule directory and do git status.
  • Many things just become clear that way!

References:

• https://stackoverflow.com/questions/7993413/git-submodules-with-modified-and-untracked-content-why-and-how-to-remove-it
• https://gist.github.com/gitaarik/8735255
• https://www.techjini.com/blog/working-with-git-submodules/
• https://medium.com/fiverr-engineering/working-with-git-submodules-ec6210801e07
• https://longair.net/blog/2010/06/02/git-submodules-explained/