PythonWise

If it won't be simple, it simply won't be. [source code] by Miki Tebeka, CEO, 353Solutions

Friday, June 10, 2016

Work with AppEngine SDK in the REPL

Working again with AppEngine for Python. Here's a small code snippet that will let you work with your code in the REPL (much better than the previous solution).
What I do in IPython is:
In [1]: %run initgae.py

In [2]: %run app.py

And then I can work with my code and test things out.

Monday, May 30, 2016

Using ImageMagick to Generate Images

One of the exercises we did this week in the Python workshop used the term "bounding box diagonal". I had a hard time to explain it to the students without an image. Google image search didn't find anything great, so I decided to create such an image.

First I tried with drawing programs, but couldn't make the rectangle a square and the circle non-oval. Then I remembered imagemagick, I have it installed and mostly use it to resize images - but it can do much more. A quick look at the examples and some trial and error, and here's the result.


And here's the script that generated it:

Saturday, April 16, 2016

Waiting for HTTP Server - Go Testing

I don't like mocking in tests. If I have a server to test, I prefer to start and instance and hit the API in my tests. Waiting for the server to start with a simple sleep is unpredictable. I prefer to start the server, try to hit an URL until it's OK or fail after a long timeout. This is a simple task with Go's select and time.After.

Tuesday, March 29, 2016

Slap a --help on it

Sometimes we write "one off" scripts to deal with certain task. However most often than not these scripts live more than just the one time. This is very common in ops related code that for some reason people don't apply the regular coding standards to.

It really upsets me when I try to see what a script is doing, run it with --help flag and it happily deletes the database while I wait :) It's so easy to add help support in the command line. In Python we do it with argparse, and we role our own in bash. Both cases it's extra 3 lines of code.

Please be kind to future self and add --help support to your scripts.

Friday, March 11, 2016

vfetch - Fetch Go Vendor Depedencies

Go 1.6 now supports vendoring. I found myself cloning dependencies to "vendor" directory, then cloning their dependencies ... This got old really fast so vfetch was born. It's a quick and dirty solution, uses "go get" with a temporary GOPATH to get the package and its dependencies, then uses rsync to copy them to the vendor directory.

Installing is the usual "go get github.com/tebeka/vfetch" then you can use "vfetch github.com/gorilla/mux".

Comment, ideas and pull requests are more than welcomed.

Tuesday, March 08, 2016

Super Simple nvim UI

I've been playing with neovim lately, enjoying it and a leaner RC file. nvim comes currently only in terminal mode and I wanted a way to spin a new window for it. Here's a super simple script (I call it e) to start a new xfce4-terminal window with nvim.

Tuesday, February 23, 2016

Removing String Columns from a DataFrame

Sometimes you want to work just with numerical columns in a pandas DataFrame. The rule of thumb is that everything that has a type of object is something not numeric (you can get fancier with numpy.issubdtype). We're going to use the DataFrame dtypes with some boolean indexing to accomplish this.

In [1]: import pandas as pd  

In [2]: df = pd.DataFrame([
   ...:     [1, 2, 'a', 3],
   ...:     [4, 5, 'b', 6],
   ...:     [7, 8, 'c', 9],
   ...: ])  

In [3]: df  
Out[3]: 
   0  1  2  3
0  1  2  a  3
1  4  5  b  6
2  7  8  c  9

In [4]: df.dtypes  
Out[4]: 
0     int64
1     int64
2    object
3     int64
dtype: object

In [5]: df[df.columns[df.dtypes != object]]
Out[5]: 
   0  1  3
0  1  2  3
1  4  5  6
2  7  8  9

In [6]:   

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