5/04/2020

Python - Conditionals and Booleans

** Conditionals and Booleans


# Comparisons:

# Equal:                   ==

# Not Equal:             !=

# Greater Than:         >

# Less Than:             <

# Greater or Equal:     >=

# Less or Equal:         <=

# Object Identity:       is

==========================================

language = 'Python'

if language == 'Python':
print("Conditional was True")


---------------------------------

Conditional was True

---------------------------------

==========================================

language = 'Python'

if language == 'Python':
print("Language is Python")
else:
print("No match")

---------------------------------

Language is Python

---------------------------------

==========================================

language = 'Java'

if language == 'Python':
print("Language is Python")
elif language == 'Java':
print("Language is Java")
else:
print("No match")

---------------------------------

Language is Java

---------------------------------

==========================================

language = 'JavaScript'

if language == 'Python':
print("Language is Python")
elif language == 'Java':
print("Language is Java")
elif language == 'JavaScript':
print("Language is JavaScript")
else:
print("No match")

---------------------------------

Language is JavaScript

---------------------------------

==========================================

# and
# or
# not

user = 'Admin'
logged_in = True

if user == 'Admin' and logged_in:
print("Admin Page")
else:
print("Bad Creds")

---------------------------------

Admin Page

---------------------------------

==========================================

# and
# or
# not

user = 'Admin'
logged_in = False

if user == 'Admin' and logged_in:
print("Admin Page")
else:
print("Bad Creds")

---------------------------------

Bad Creds

---------------------------------

==========================================

# and
# or
# not

user = 'Admin'
logged_in = False

if user == 'Admin' or logged_in:
print("Admin Page")
else:
print("Bad Creds")

---------------------------------

Admin Page

---------------------------------

==========================================

# and
# or
# not

user = 'Admin'
logged_in = False

if not logged_in:
print("Please Log In")
else:
print("Welcome")


---------------------------------

Please Log In

---------------------------------
# False Valuse:
# False
# None
# Zero of any numeric type
# Any empty sequence. ex) '', (), [].
# Any empty mapping. ex) {}.


==========================================

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

print(a == b)

print(a is b)

print(id(a))
print(id(b))

b = a

print(a is b)

print(id(a) == id(b))

---------------------------------

True
False
15258632
16011944
True
True

---------------------------------

==========================================


condition = False

if condition:           # 조건이 참일 때만 실행.
print("Evaluated to True")
else:
print("Evaluated to False")


---------------------------------

Evaluated to False

---------------------------------

==========================================

condition = True

if condition:
print("Evaluated to True")
else:
print("Evaluated to False")


---------------------------------

Evaluated to True

---------------------------------

==========================================

condition = 10

if condition:
print("Evaluated to True")
else:
print("Evaluated to False")

---------------------------------

Evaluated to True

---------------------------------

==========================================

# False Valuse:
# False
# None
# Zero of any numeric type
# Any empty sequence. ex) '', (), [].
# Any empty mapping. ex) {}.


---------------------------------

--------------------------------------------------------------------------------