# Becoming Pythonic

# Variables
# Python
x = 7
y = 3
z = x + y # 10

# Pythonic
x,y = 7,3
z = x + y

# Sorting without a sort() or reverse()
# Python
a = 10
b = 5
## print a,b  10,5
print(a,b)
## asserting 5,10
temp = a # original value of a in temp  temp = 10
a = b  # assign the current value of b as a  a = 5
b = temp # assing the current value of temp as b  b = 10
# a = 5, temp = 10, b = 10
print(a,b) # 5,10

# Pythonic
a,b = 10,5
print(a,b)
a,b = b,a
print(a,b)

# List Comprehension
# Python
## Create an empty list in memory
n = []
## Append elements to the list
for x in range(10):
    n.append(x)
    x + 1
print(n)

# Pythonic
# Create the list, append the elements then object in memory
n = [x + 1 for x in range(10)] # no append()
print(n)

# Dictionary Comprehension
# Collection
names = ["Bob", "Joe", "Mary"]  #  { fname: Bob}
# Python
## Create an empty dict in memory
name_lengths = {}
## Loop thru the list and assign values
for name in names:
    name_lengths[name] = len(name)
print(name_lengths)
fname_names = [] # empty list
for name in names:
    fname_name = {'fname': name}
    fname_names.append(fname_name)
print(fname_names) # [ {k:v}, {k:v}, {k:v} ]

# Pythonic
name_lengths = { name: len(name) for name in names }
print(name_lengths)
fname_names = [{'fname': name} for name in names]
print(fname_names) # [ {k:v}, {k:v}, {k:v} ]

# Same rules apply to tuple () and set {}
# Python
## Create the empty collection  ()  {}
## then loop
# Pythonic
# Compress the local var and the loop into the collection
# {condition for x in ys loop}
# tuple you have to do it as a list then cast to tuple

# Tuple Casting due to immutable properties
ccInfo = ()
print(type(ccInfo)) # tuple
print(ccInfo) # prints an empty tuple

# Populate a list !set
t_ccInfo = ('4111 5255 4521 4152', '12/25', '523')
print(t_ccInfo)

# Convert to list and update position 2
def updateCVC():
    t_ccInfo = ('4111 5255 4521 4152', '12/25', '523')
    new_cvc = input("CVC Code invalid, please enter a valid 3 digit code: ")
    l_ccInfo = list(t_ccInfo)
    l_ccInfo[2] = new_cvc   # assertion
    print(l_ccInfo)
    # GC Class both none or del keyword
    #l_ccInfo = None # unassigned variable
    #del l_ccInfo # dispose()
    t_ccInfo = tuple(l_ccInfo)  # tuple
    return t_ccInfo

# print(updateCVC())

# Custom Iterables to improve or make pythonic<ys> the for x in ys loop
# Python
## Using the iterable() for the in keyword inside the object
class NonPythonicIterable: # __init__  iterate() 
    def __init__(self, max):
        self.max = max # 3 defined interator

    def iterate(self):
        num = 0 # control
        while num < self.max: # condition  while 0 < 3
            yield num
            num += 1 # increment working with function()
            # num + 1 # addition operator working with variable

# create an instance of the class and use the iterate()
iterator = NonPythonicIterable(3)
for num in iterator.iterate():
    print(num)

# Pythonic
## Use the interable() for the in as Property __next__ on the class
class PythonicIterable: # __init__ iterate() __next__
    # move control from iterate() to __init__
    def __init__(self, max):
        self.max = max
        self.num = 0
    
    # use the built in Property __iter__ instead of a function() / iterate()

    def __iter__(self):
        return self  # handle the return

    # def __next__ Property to handle the condition
    def __next__(self):
        if self.num < self.max:
            num = self.num
            self.num += 1 # increment instead of addition operator +
            return num
        raise StopIteration

# ys is coming from __next__
iterator = PythonicIterable(3)
for num in iterator:
    print(num)

# Regular Expression
import re
# test email patterns
emails = ["philipm@onlc.com", "www.onlc.com", "philip.matusiak@gmail.comm", "bob123@hotmail.us"]
# Python use the if keyword
def validate_email(email):
    if re.match(r"^[a-zA-Z0-9_.]+@[a-zA-Z0-9]+?\.[a-zA-Z]{2,3}$", email):
        return True
    else:
        return False

for email in emails:
    if validate_email(email):
        print(f"{email} is a valid email address.")
    else:
        print(f"{email} is an invalid email address.")

# Pythonic use the bool() to replace the if pattern lamba to replace the if in the for loop
def is_valid_email(email):
    return bool(re.match(r"^[a-zA-Z0-9_.]+@[a-zA-Z0-9]+?\.[a-zA-Z]{2,3}$", email))

for email in emails:
    print(f"{email} is {'a valid' if is_valid_email(email) else 'not a valid'} email address.") # ternary operator or lambda