Quirky Python

quirky_python.py

# File  : quirky_python.py
# Author: AugFJTan
# Date  : 25/09/18

############################################
# Swap values without a temporary variable #
############################################

# Initial values
a = 5
b = 2

# Expect "a = 5, b = 2"; nothing unusual here
print("a = {0}, b = {1}".format(a, b))

# Swap 'em!
a, b = b, a

# Output is "a = 2, b = 5"!
print("a = {0}, b = {1}".format(a, b))


############################################
# Lists and tuples: similar but different? #
############################################

# Yes, these are valid, but are they equivalent?
L = [3.5, "Hello", 124]
T = (3.5, "Hello", 124)

# Print list
for l in L:
	print(l)

# Print tuple
for t in T:
	print(t)

# Assign value
L[0] = 7.2 # No problem here
T[0] = 7.2 # Error!


################
# Nested lists #
################

L = [3, [4,5], [[6]]]

for l in L:
	print(l)

# Output:
# 3
# [4, 5]
# [[6]]


###################
# Lists in tuples #
###################

# We saw that tuples are immutable,
# but then again, lists are mutable...
T = (2.6, "Hello", [4,5,6])
T[2].append(7) # Totally valid!


###############################################
# All class variables and methods are public! #
###############################################

# Access modifiers? Pfft... who needs such complex abstractions?
class Test:
	def __init__(self):
		self.public    = "Public!"
		self.protected = "Some sensitve data"
		self.private   = "Top secret info"
	
	def private_method(self):
		return "Encryption key"

t = Test()
t.public

# Nothing will stop you from doing this:
t.private
t.protected
t.private_method()

# Instead, use convensions to denote private and protected
class Test:
	def __init__(self):
		self.public     = "Public!"
		self._protected = "Some sensitve data"
		self.__private  = "Top secret info"
	
	def __private_method(self):
		return "Encryption key"