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Python beginner's mistakes

Python beginner's mistakes
Every Python programmer had to learn the language at one time, and started out as a beginner. Beginners make mistakes. This article highlights a few common mistakes, including some I made myself. Beginner's mistakes are not Python's fault, nor the beginner's. To put it another way, the mistakes in this article are often cases of "the wrong tool for the job", rather than coding errors or sneaky language traps. Mistake 1: trying to do low-level operations Python is sometimes described as a VHLL, a Very High-Level Language. This doesn't mean that it isn't possible to do these things with Python; but it's probably just not the right language for these jobs. Mistake 2: writing "language X" code in Python This is a mistake that is almost unavoidable. Some notorious symptoms of "language X" code, and the languages that may cause them: The point here is not to slam the language that you're used to (although that is always fun ;-). This one requires some clarification. Some advice

The Django Book Software Carpentry The Problem Many scientists and engineers spend much of their lives writing, debugging, and maintaining software, but only a handful have ever been taught how to do this effectively: after a couple of introductory courses, they are left to rediscover (or reinvent) the rest of programming on their own. The result? Most spend far too much time wrestling with software when they'd rather be doing research, but still have no idea how reliable or efficient that software is. The Solution This site presents an intensive course on basic software development practices for scientists and engineers.

Learning with Python Navigation How to Think Like a Computer Scientist¶ Learning with Python¶ 2nd Edition (Using Python 2.x) by Jeffrey Elkner, Allen B. Last Updated: 21 April 2012 Copyright NoticeForewordPrefaceContributor ListChapter 1 The way of the programChapter 2 Variables, expressions, and statementsChapter 3 FunctionsChapter 4 ConditionalsChapter 5 Fruitful functionsChapter 6 IterationChapter 7 StringsChapter 8 Case Study: CatchChapter 9 ListsChapter 10 Modules and filesChapter 11 Recursion and exceptionsChapter 12 DictionariesChapter 13 Classes and objectsChapter 14 Classes and functionsChapter 15 Classes and methodsChapter 16 Sets of ObjectsChapter 17 InheritanceChapter 18 Linked ListsChapter 19 StacksChapter 20 QueuesChapter 21 TreesAppendix A DebuggingAppendix B GASPAppendix c Configuring Ubuntu for Python DevelopmentAppendix D Customizing and Contributing to the BookGNU Free Document License Search Page © Copyright 2010, Jeffrey Elkner, Allen B.

PEP 20 -- The Zen of Python Abstract Long time Pythoneer Tim Peters succinctly channels the BDFL's guiding principles for Python's design into 20 aphorisms, only 19 of which have been written down. The Zen of Python Beautiful is better than ugly. Easter Egg >>> import this Copyright This document has been placed in the public domain. Learning to Program with Python Here we will use the python programming language to make a game of hangman, starting from scratch, working on a Macintosh. Python comes with OS X, so nothing special needs to be installed to follow along on your Mac. To use python on Windows, you can download and install python here. If you do not want to install python or you want to learn a newer and popular python-like language that runs in any modern browser, you can read Learning to Program with CoffeeScript, at davidbau.com/coffeescript. It takes a couple hours to learn enough programming to make a simple game. We will learn about: Memory and naming Computer arithmetic Using and learning libraries How to make a program Input and output Loops and choices Connecting to the internet At the end we will have a game we can play. This page was originally posted at for teaching a small group of third-graders. Running Python Go to the "Utilities" folder on your Mac and run "Terminal." Keeping a Secret Don't worry. #! #!

The Hitchhikers Guide to Python! — pythonguide 0.0.1 documentation Greetings, Earthling! Welcome to The Hitchhiker’s Guide to Python. This is a living, breathing guide. If you’d like to contribute, fork us on GitHub! This handcrafted guide exists to provide both novice and expert Python developers a best practice handbook to the installation, configuration, and usage of Python on a daily basis. This guide is opinionated in a way that is almost, but not quite, entirely unlike Python’s official documentation. Note The use of Python 3 is highly preferred over Python 2. Let’s get started! Getting Started with Python New to Python? Properly Install Python on your system: Using Virtualenvs with Pipenv: Python Development Environments This part of the guide focus on the Python development environment, and the best-practice tools that are available for writing Python code. Writing Great Python Code This part of the guide focuses on the best-practices for writing Python code. Scenario Guide for Python Applications Shipping Great Python Code Additional Notes

The "Invent with Python" Blog I frequently see a problem when people (especially techies) try to teach programming to someone (especially non-techies). Many programming tutorials begin with basic programming principles: variables, loops, data types. This is both an obvious way to teach programming and almost certainly a wrong way to teach programming. It’s wrong because nobody wants to learn how to program. If you are teaching a class of adults who are paying with their own money for an education, then this is an appropriate and direct way to teach programming. But for the casually interested or schoolchildren with several activities competing for their attention, programming concepts like variables and loops and data types aren’t interesting in themselves. Here are my five pieces of advice to people who want to teach programming or create programming tutorials: 1. But people can feel the limitations that these programs have. 2. 3. I began learning BASIC in the third grade. 4. 5. Enough said.

PEP 8 -- Style Guide for Python Code Code should be written in a way that does not disadvantage other implementations of Python (PyPy, Jython, IronPython, Cython, Psyco, and such).For example, do not rely on CPython's efficient implementation of in-place string concatenation for statements in the form a += b or a = a + b. This optimization is fragile even in CPython (it only works for some types) and isn't present at all in implementations that don't use refcounting. In performance sensitive parts of the library, the ''.join() form should be used instead. This will ensure that concatenation occurs in linear time across various implementations.Comparisons to singletons like None should always be done with is or is not, never the equality operators.Also, beware of writing if x when you really mean if x is not None -- e.g. when testing whether a variable or argument that defaults to None was set to some other value. The other value might have a type (such as a container) that could be false in a boolean context!

Learn Python in 10 minutes NOTE: If you would like some Python development done, my company, Stochastic Technologies, is available for consulting. This tutorial is available as a short ebook. The e-book features extra content from follow-up posts on various Python best practices, all in a convenient, self-contained format. All future updates are free for people who purchase it. Preliminary fluff So, you want to learn the Python programming language but can't find a concise and yet full-featured tutorial. Properties Python is strongly typed (i.e. types are enforced), dynamically, implicitly typed (i.e. you don't have to declare variables), case sensitive (i.e. var and VAR are two different variables) and object-oriented (i.e. everything is an object). Getting help Help in Python is always available right in the interpreter. >>> help(5)Help on int object:(etc etc) >>> dir(5)['__abs__', '__add__', ...] >>> abs. Syntax Python has no mandatory statement termination characters and blocks are specified by indentation. Strings

BeginnersGuide New to programming? Python is free and easy to learn if you know where to start! This guide will help you to get started quickly. Chinese Translation/中文版入门 New to Python? Read BeginnersGuide/Overview for a short explanation of what Python is. Getting Python Next, install the Python 3 interpreter on your computer. There are also Python interpreter and IDE bundles available, such as Thonny. At some stage, you'll want to edit and save your program code. Learning Python Next, read a tutorial and try some simple experiments with your new Python interpreter. If you have never programmed before, see BeginnersGuide/NonProgrammers for a list of suitable tutorials. Most tutorials assume that you know how to run a program on your computer. Some sites offer in-browser coding for those who want to learn Python: Print a cheat sheet of the most important Python features and post it to your office wall until you know the basics well. Need Help? Need help with any of this? Complete list of Beginner's Guide pages

Python - Notes You have seen how you can reuse code in your program by defining functions once. What if you wanted to reuse a number of functions in other programs that you write? As you might have guessed, the answer is modules. There are various methods of writing modules, but the simplest way is to create a file with a .py extension that contains functions and variables. Another method is to write the modules in the native language in which the Python interpreter itself was written. A module can be imported by another program to make use of its functionality. Example (save as module_using_sys.py): import sys print('The command line arguments are:')for i in sys.argv: print i print '\n\nThe PYTHONPATH is', sys.path, '\n' $ python module_using_sys.py The command line arguments are: module_using_sys.py we are arguments The PYTHONPATH is ['/tmp/py', # many entries here, not shown here '/Library/Python/2.7/site-packages', '/usr/local/lib/python2.7/site-packages'] How It Works 11.1. 11.2. 11.3. 11.4. 11.5.

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