Time a Python Function

In one of the previous articles (Measure Time in Python – time.time() vs time.clock()), we learned how to use the module timeit to benchmark a program. Since the program we timed in that article includes only raw statements instead of functions, we’re going to explore how to actually time a function in Python. Time a […]

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Hashing Files with Python

Remember that a hash is a function that takes a variable length sequence of bytes and converts it to a fixed length sequence. Calculating a hash for a file is always useful when you need to check if two files are identical, or to make sure that the contents of a file were not changed, […]

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Hashing Strings with Python

A hash function is a function that takes input of a variable length sequence of bytes and converts it to a fixed length sequence. It is a one way function. This means if f is the hashing function, calculating f(x) is pretty fast and simple, but trying to obtain x again will take years. The value returned […]

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How to Recursively Copy a Folder (Directory) in Python

Ever tried to copy a directory/folder in Python? Ever failed? No matter. Try again! If you haven’t already read it, look at the article How to Copy a File in Python with shutil for an explanation of how to copy files with shutil. Recursively Copying a Directory/Folder of Files in Python In the article that […]

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How to Rename (Move) a File in Python

Renaming (in Python it’s known as moving) a file in Python is really simple, and can be done in very few lines thanks to a handy module called shutil. shutil has a function called move that does precisely what the function name implies. It moves files or directories from one location to another. Here’s a […]

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How to Slice Custom Objects/Classes in Python

For an introduction to slicing, please view the article How to Slice Lists/Arrays and Tuples in Python. Slicing Your Own Python Objects Alright, that’s all cool, now we know how to slice. But how do we slice our own objects? If I implement an object that has a list, or custom data structure, how do […]

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How to See if a String Contains Another String in Python

Ever wanted to see if a string contains a string in Python? Thought it was going to be complicated like C? Think again! Python implements this feature in a very easy to read and easy to implement fashion. There are two ways of doing it, and some will like one way better than the other, […]

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How to Copy a File in Python with shutil

So you want to know how to copy a file in Python? Good! It’s very useful to learn and most complex applications that you may design will need at least some form of copying files. Copying a Single File in Python Alright, let’s get started. This first section will describe how to copy a single […]

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How to Slice Lists/Arrays and Tuples in Python

So you’ve got an list, tuple or array and you want to get specific sets of sub-elements from it, without any long, drawn out for loops? Python has an amazing feature just for that called slicing. Slicing can not only be used for lists, tuples or arrays, but custom data structures as well, with the […]

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How to Get a Sub-string From a String in Python – Slicing Strings

So how do you get a sub-string in Python? Well, Python has a handy dandy feature called “slicing” that can be used for getting sub-strings from strings. But first, we have to go over a couple of things to understand how this works. Slicing Python Objects Strings, in Python, are arrays of characters, except they […]

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