Python 101 - Part 1

PEP	Python Enhancements Proposal (guidelines) PEP 8: Style Guide For Python Code PEP 20: Zen of Python
Indentation	Used to mark blocks, curly braces no longer needed Recommendation is to use 4 spaces for indentation, be consistent and not to mix spaces with tabs
Modules	- Use modules available in Python e.g.: import math After importing use the module name to call functions: math.sqrt(5) math.factorial(5) from math import factorial -> factorial(5) # avoid using math from math import factorial as fac -> fac(5) #shorter name
Help (in REPL cmd)	- Get help on a module help(math) - Get help on a function help(math.sqrt) help(math.factorial)
int, float	int(10), int(10.2), int(“10”) float(10), float(10.2), float(“10.2”)
Nan,inf	float(“nan”) # not a number float(“inf”) # infinity
None	Represents absence of value a = None a Is None # returns True
Boolean	0: falsy Non-zero (inc. negative): truthy bool(0) bool(0.0): # False bool(-1) # True For Lists If list is empty: bool(list) returns False bool([]) # False bool([1,2,3]) # True For strings: bool(“”) # False bool(“a”) # True bool(“      “) # all white spaces, True if “ihavesomething”:  # this is True     print(“this is True”)
Raw strings	path = r’C:\Users\Documents\Course’