Author Archives: Ruben Sanchez-Garcia

Command-Line Interfaces (CLIs), argparse.ArgumentParser and some of my tricks.

Command-Line Interfaces (CLIs) are one of the best ways of providing your programs with useful parameters to customize their execution. If you are not familiar with CLI, in this blog post we will introduce them. Let’s say that you have a program that reads a file, computes something, and then, writes the results into another file. The simplest way of providing those arguments would be:

$ python mycode.py my/inputFile my/outputFile
### mycode.py ###
def doSomething(inputFilename):
    with open(inputFilename) as f:
        return len(f.readlines())

if __name__ == "__main__":
    #Notice that the order of the arguments is important
    inputFilename = sys.argv[1]
    outputFilename = sys.argv[2]

    with open(outputFilename, "w") as f:
        f.write( doSomething(inputFilename))
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Linux Horror Stories and Protection Spells (Volume I)

Don’t get me wrong. I love Linux. After many years of using it, I ended up appreciating how flexible, potent, and even beautiful it is. However, using Linux has never been a bed of roses and every single Linux user that I know has had to deal with many problems since the very beginning. Indeed, I still remember how frustrating installing my first Linux machine was, especially after realizing that my network card was not working. Had I given up, I would never have written this post.

Although many of the problems that I faced while using Linux are related to updates and drivers (how painful NVidia drivers updates can be, I will write another post about that in the future), I must recognize that on many other occasions I was the only one responsible for such problems. Consequently, I want to warn the reader against a couple of those mistakes I made in the past and provide some tips about how to deal with them.

My worst nightmare: rm –r * 

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