adding more tut

Author: lev epshtein

function/functions.py

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+## 1 basic function definition, empty function
+
+# def hello_func():
+#     pass
+#
+# print(hello_func())
+
+## 2 function defenition
+# def hello_func():
+#     print('hello function!')
+#
+# hello_func()
+# hello_func()
+# hello_func()
+# hello_func()
+# hello_func()
+
+## 3 return of function and method on return
+# def hello_func():
+#     return 'hello function!'
+# print(hello_func())
+# print(hello_func().upper())
+
+## function arguments, to show : error when without argument, default value argument, couple arguments
+# def hello_func(greeting):
+#     return '{} function!'.format(greeting)
+#
+# print(hello_func())
+
+#####
+# DRY principle keep your code clean without repeats. Don't repeat yourself !
+# Concentred on input and return value of functions
+#####
+
+# Function with args and kwargs
+# def student_info(*args, **kwargs):
+#     print(args)
+#     print(kwargs)
+# #
+# student_info('Math', 'Art', name='Jhon', age=22)
+# print ("---")
+# courses = ['Math', 'Art']
+# info = {'name':'Jhon', 'age':22}
+
+# student_info(courses, info)
+# print ("---")
+# student_info(*courses, **info)

function/lambda_fnc.py

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+# lambda expretion or lambda function
+# anonymous funtion - function that don't have name bounce to it
+
+# regular function
+# def p(num):
+#     return num ** 2
+# print(p(4))
+# print(type(p))
+
+# lambda function general syntax :
+# y = lambda x: x ** 2
+# print(y(4))
+# print(y)
+
+## Why is usefull, for example :
+# def h(n):
+#     return lambda x: (x + n) ** 2
+#
+# c = h(3)
+# b = h(0)
+# print(c)
+# print(b)
+#
+# print (b(2))
+# print(c(2))
+
+##
+# Another example build quadratic functions
+# def build_quadratic_runction(a, b, c):
+#     """Returns the function f(x)=ax^2 + bx + c"""
+#     return lambda x: a*x**2 + b*x + c
+#
+# f = build_quadratic_runction(2, 3, -5)
+#
+# print(f(0))
+# print(f(1))
+# print(f(2))
+#
+# print(build_quadratic_runction(3, 0, 1)(2)) # 3x^2+1 evaluated for x=2

generators/generator.py

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+# def square_numbers(nums):
+#     for i in nums:
+#         yield (i*i)
+
+
+# my_nums = square_numbers([1, 2, 3, 4, 5])
+
+
+# print(next(my_nums))
+# print(next(my_nums))
+# print(next(my_nums))
+# print(next(my_nums))
+# print(next(my_nums))
+
+# for num in my_nums:
+#     print(num)
+
+# list comprehention advance
+
+# my_nums = list(x*x for x in [1,2,3,4,5])
+
+# print (my_nums)

modules/__pycache__/mymath.cpython-38.pyc

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+"""mymath - example math module"""
+pi = 3.14159
+def area(r):
+        """area(r): return the area of a circle with radius."""
+        global pi
+        return(pi * r * r)
+
+# In REPL
+# >>> import mymath
+# >>> mymath.__doc__
+# >>> from mymath import pi
+# >>> pi

modules/mymath.py

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+virtualenv - you can separete differnt python environments
+
+- pip install virtualenv
+- mkdir Environment
+- cd Environment
+- virtualenv project1_env/ 
+- cd project1_env/Scripts
+- activate.bat
+
+Let's install some packages :
+- pip install numpy
+- pip install pytz
+- pip install psutil
+- pip freeze --local > ..\..\requirments.txt
+- rm -rf project1_env/
+
+Let's create second project with different version of python and install modules
+- virtualenv project2_env/ 
+- virtualenv project2_env/ 
+- cd project2_env/Scripts
+- activate.bat
+- pip install -r ..\..\requirements.txt

virtualenv/virtualenv-tutorial.txt

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+## Basic scraping 
+# from https://github.com/pricing/
+# use inspect in browser to find HTML path
+# Install lxml and request:
+# pip install lxml request
+
+
+from lxml import html
+import requests
+
+page = requests.get('https://github.com/pricing/')
+tree = html.fromstring(page.content)
+print("Page Object:", tree)
+plans = tree.xpath('//h3[@class="h2-mktg text-bold mt-1"]/text()')
+pricing = tree.xpath('//h3[@class="h1-mktg lh-condensed-ultra my-3 py-1"]/text()')
+print("Plans:", plans, "\nPricing:", pricing)