lambda, conditions

Author: lev epshtein

if_else_elif/conditions.py

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+# Object Identity: is
+# Operation: and or not
+
+
+# General explanation
+# if True:
+#     print('Conditional was True')
+
+# 1 with var
+# language = 'Python'
+# if language == 'Python':
+#     print('Conditional was True')
+
+# Comparisons:
+# Equal:            ==
+# Not Equal:        !=
+# Greater Than:     >
+# Less Than:        <
+# Greater or Equal: >=
+# Less or Equal:    <=
+# Object Identity:  is              # if the value have same id, same object in memory
+
+## 2 else statement
+
+# language = 'Python'
+#
+# if language == 'Python':
+#     print('Conditional was True')
+# else:
+#     print('No match')
+
+## 3 elif
+language = 'Python'
+
+if language == 'Python':
+    print('language is python')
+elif language == 'Java':
+    print('language is java')
+else:
+    print('No match')
+
+## 4 and , or , not operation
+
+# user = 'Admin'
+# logged_in = True
+
+# if user == 'Admin' and logged_in:
+#     print('Admin page')
+# else:
+#     print('Bad Creds')
+
+# not examle
+# if not logged_in:
+#     print('Please Log in')
+# else:
+#     print('Welcome')
+
+## 5 is operation
+# object id explanation
+# a = [1,2,3]
+# b = [1,2,3]
+#
+# print(a == b)
+# print (a is b)
+#
+# print(id(a))
+# print(id(b))
+
+## True and False values
+# False Values:
+    # False
+    # None
+    # Zero of any numeric type
+    # Any empty sequence. For example, '', (), [].
+    # Any empty mapping. For example, {}.
+
+# condition = False
+#
+# if condition:
+#     print('Evaluated to True')
+# else:
+#     print('Evaluated to False')

loops/lambda.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