@ Python's Matrix Multiplication Operator
Posted by Aly Sivji in Quick Hits
2017 will forever be etched in our memories as the year Python overtook R to become the leading language for Data Science. There are many factors that play into this: Python's simple syntax, the fantastic PyData ecosystem, and of course buy-in from Python's BDFL.
PEP 465 introduced the @ infix operator that is designated to be used for matrix multiplication. The acceptance and implementation of this proposal in Python 3.5 was a signal to the scientific community that Python is taking its role as a numerical computation language very seriously.
Adding Function Arguments to pytest Fixtures
Posted by Aly Sivji in Quick Hits
Testing is one of my favourite things about programming. There is nothing like the piece of mind that comes from being able to modify code without having to worry about breaking something.
Like most Python programmers, I started testing using the PyUnit framework (aka unittest) included in Python's Standard Library. PyUnit is part of the xUnit
Increasing namedtuple Readability with Type Hints
Posted by Aly Sivji in Quick Hits
Dynamic typing refers to programs checking variable types at runtime versus compile time. By not having to define the variable type as we write code, we can work faster and take advantage of duck typing.
On the other hand, we do miss out on some benefits that types bring. Similiar to how the principles of test-driven development force us to write smaller, more testable functions, thinking about types improves software design by making us cognizant of the values our variables hold as well as the values our functions can return.
Python Testing: Mocking Functions based on Input Arguments
Posted by Aly Sivji in Quick Hits
In Python, functions are objects. This means we can return them from other functions.
In this Quick Hit, we will use this property of functions to mock out an external API with fake data that can be used to test our internal application logic.
Note: I previously used Python functions to simulate the behavior of a case statement
Python Dictionaries Require Hashable Keys
Posted by Aly Sivji in Quick Hits
I was floored when I discovered I could use tuples (and namedtuples) as Python dictionary keys.
Turns out this is not totally correct.
Started reading Fluent Python and learned that tuples are not always immutable. For instance, they can contain list elements...
Dictionary Dispatch
Posted by Aly Sivji in Quick Hits
ChiPy hosts Python Project Night on the 3rd Thursday of every month. Groups of four are given an hour to work through a structured exercise with each person spending 15 minutes at the keyboard writing code. At the end of the hour, one group is selected to present their solution.
A Gentle Introduction to Context Managers: The Pythonic Way of Managing Resources
Summary¶
- Explore
withstatements and the context manager protocol- Implement context manager class to query MongoDB
- Convert
try...finallyblock towithblock and increase code readability
I recently read Steve McConnell's Code Complete to level up my software development skill-set. The book has helped me become more deliberate about programming and problem solving in general. Before I sit down to write a single line of code, I take some time to plan out the work I am going to do versus code by the seat of my pants
Tuples (and namedtuples) as Python Dictionary Keys
Posted by Aly Sivji in Quick Hits
Was reading the Python design FAQs and saw that immutable elements can be used as dictionary keys.
Wait a minute.... tuples are immutable, can they be used as dictionary keys? YES!