The module function timeit.timeit(stmt, setup, timer, number) accepts four arguments:
• stmt which is the statement you want to measure; it defaults to ‘pass’.
• setup which is the code that you run before running the stmt; it defaults to ‘pass’. We generally use this to import the required modules for our code.
• timer which is a timeit.Timer object; it usually has a sensible default value so you don’t have to worry about it.
• number which is the number of executions you’d like to run the stmt.

Read this page for more information:


https://www.geeksforgeeks.org/timeit-python-examples/

Python '!=' Is Not 'is not': Comparing Objects in Python

In this tutorial, you’ll learn:
• What the difference is between object equality and identity
• When to use equality and identity operators to compare objects
• What these Python operators do under the hood
• Why using is and is not to compare values leads to unexpected behavior
• How to write a custom __eq__() class method to define equality operator behavior

https://realpython.com/python-is-identity-vs-equality/

None is evaluated as False so you can write

>>> results = None
>>> print(results or "No results")

============24th April 2020=======

# "is" vs "=="

>>> a = [1, 2, 3]
>>> b = a

>>> a is b
True
>>> a == b
True

>>> c = list(a)

>>> a == c
True
>>> a is c
False

# • "is" expressions evaluate to True if two
# variables point to the same object

# • "==" evaluates to True if the objects
# referred to by the variables are equal

———First class Functions—————

# Functions are first-class citizens in Python:

# They can be passed as arguments to other functions,
# returned as values from other functions, and
# assigned to variables and stored in data structures.

>>> def myfunc(a, b):
... return a + b
...
>>> funcs = [myfunc]
>>> funcs[0]
<function myfunc at 0x107012230>

>>> funcs[0](2, 3)
5

# Because Python has first-class functions they can
# be used to emulate switch/case statements

def dispatch_if(operator, x, y):
if operator == 'add':
return x + y
elif operator == 'sub':
return x - y
elif operator == 'mul':
return x * y
elif operator == 'div':
return x / y
else:
return None


def dispatch_dict(operator, x, y):
return {
'add': lambda: x + y,
'sub': lambda: x - y,
'mul': lambda: x * y,
'div': lambda: x / y,
}.get(operator, lambda: None)()


>>> dispatch_if('mul', 2, 8)
16

>>> dispatch_dict('mul', 2, 8)
16

>>> dispatch_if('unknown', 2, 8)
None

>>> dispatch_dict('unknown', 2, 8)
None

——————List Operations—————

# Python's list slice syntax can be used without indices
# for a few fun and useful things:

# You can clear all elements from a list:
>>> lst = [1, 2, 3, 4, 5]
>>> del lst[:]
>>> lst
[]

# You can replace all elements of a list
# without creating a new list object:
>>> a = lst
>>> lst[:] = [7, 8, 9]
>>> lst
[7, 8, 9]
>>> a
[7, 8, 9]
>>> a is lst
True

# You can also create a (shallow) copy of a list:
>>> b = lst[:]
>>> b
[7, 8, 9]
>>> b is lst
False

# Python's list comprehensions are awesome.

vals = [expression
for value in collection
if condition]

# This is equivalent to:

vals = []
for value in collection:
if condition:
vals.append(expression)

# Example:

>>> even_squares = [x * x for x in range(10) if not x % 2]
>>> even_squares
[0, 4, 16, 36, 64]

———Sorting is easy in Python———

# Python has a HTTP server built into the
# standard library. This is super handy for
# previewing websites.

# Python 3.x
$ python3 -m http.server

# Python 2.x
$ python -m SimpleHTTPServer 8000

# (This will serve the current directory at
# http://localhost:8000)

# Python 3.5+ supports 'type
# annotations' that can be
# used with tools like Mypy
# to write statically typed Python:

def my_add(a: int, b: int) -> int:
return a + b