#!/usr/bin/env python
# coding: utf-8

# # SAISOFT PYT-PR:  Session 10
# 
# ### The Ecosystem includes Many Languages
# 
# The Python ecosystem involves Python in using other languages and rule sets such as:
# 
# * SQL (Structured Query Language)
# * Regexes (Regular Expressions)
# * Markdown (for Jupyter Notebooks)
# * magic (% and %% inside Notebooks and I-Python)
# * APIs (every library and framework comes with one)
# * Sphinx (documentation generator, uses reStructured Text)
# * JavaScript (used with web frameworks)
# * Template Languages (example: Jinja)
# * HTML / CSS (naturally)
# * Widget Toolkits (more APIs for GUIs)
# * IDEs (such as Spyder, Pycharm, Sublime Text, vi, emacs)
# 
# and so much else.

# Lets take a look at another Standard Library module and talk about what it does.  
# 
# Hash functions are not designed to preserve content.  They don't encrypt.  They're about associating some unique finger print with any hashable object.

# In[ ]:


import hashlib
m = hashlib.sha256()
m.update(b"Nobody inspects")
m.update(b" the spammish repetition")
m.digest()


# Expected:
# <pre>
# b'\x03\x1e\xdd}Ae\x15\x93\xc5\xfe\\\x00o\xa5u+7\xfd\xdf\xf7\xbcN\x84:\xa6\xaf\x0c\x95\x0fK\x94\x06'
# </pre>
# 

# In[ ]:


result = hashlib.sha256(b"Nobody inspects the spammish repetition").hexdigest()
result


# In[ ]:


print("Digest size", m.digest_size)
print("Block size ", m.block_size)


# In class, we looked at a passwords database that doesn't save actual passwords, only hashes thereof.  Even system administrators with the keys to the database, have no means to force a hash to run backwards to regain the phrase which was behind it.  A hash is a one way street.
# 
# ### LAB:
# 
# Check the Python docs and run the above example with sha224 instead.  Do you get past this assertion (unit test)?

# In[ ]:


# Uncomment me to check your result
# assert result == 'a4337bc45a8fc544c03f52dc550cd6e1e87021bc896588bd79e901e2'