======Python====== * [[https://www.python.org/dev/peps/pep-0008/|PEP 8 -- Style Guide for Python Code]] * [[https://pep8.org/]] * [[Python Modules and Packages]] * [[Python Tools]] * [[python:Handling Dates]] ======Core Elements & Constructs====== =====Lists===== l = [] l.append("alpha") l.append("beta") for e in l: print(e) =====Dictionaries===== d = {'alpha': 'plucky', 'beta': 'scrappy'} print(d['alpha']) print(d.get('alpha')) del d['alpha'] # Remove all elements. d.clear() d['gamma'] = 'spunky' # Delete the dictionary itself. del d b={} => None b["alpha"] = 10 => None b => {'alpha': 10} del b["alpha"] => None b => {} ======Basic Structures and Constructs====== * If the %%__name__%% variable is set to %%__main__%% the module is being loaded as a main script and program entry point. Otherwise it's being loaded as a library module. if __name__ == "__main__": print("Hello World.") else: pass ======Conditionals====== num = 100 a = ["alpha", "beta", "gamma"] if "beta" in a: pass if num > 10: pass elif num < 10: pass else: pass ======Loops/Iteration====== colors = ["red", "green", "blue"] for c in colors: print("%s" % c) =====Iterate over keys and values of dictionary==== for k, v in dict.items(): print(v) for k in dict.keys(): print(k + "\n") for v in dict.values(): print(v + "\n") =====Iterate over indicies and values of sequence===== a = ["a", "b", "c"] for k, v in enumerate(a): print("%s, %s\n" % (k,v)) ======Common Elements and Ways====== ======Determine if variable is defined====== It might be a code smell/anti-pattern to test whether or not an identifier is defined. That is, testing whether a variable is defined considered harmful. =====Method 1====== x_exists = 'x' in locals() or 'x' in globals() =====Method 2====== try: x except NameError: x_exists = False else: x_exists = True =====Method 3===== hasattr(a, 'property') =====Method 4===== if args.file is None or len(args.file) == 0: pass =======Resources/References====== * [[http://docs.python-guide.org/en/latest/|The Hitchhiker’s Guide to Python]] * [[https://realpython.com/|Real Python]], tutorials and other learning resources