# Chapter7.py
# Pythonic -> readability, framework, resource allocation

# Variable Declaration -> readability, resource allocation
print("===== Variable Declaration Example =====")
# Python Syntax
a = 7
b = 4
# Output Python Syntax
c = a * b
print(c)
# Pythonic
a,b = 7,4
# Output Pythonic
c = a * b
print(c)
print("===== End of Variable Declaration Example =====")

# List Comprehension
print("===== List Comprehension Example =====")
## data set
data = ['Bob', 'Joe', 'Mary']
## Python syntax using the range()
## len() and range() manually defined with in keyword
for x in range(0, len(data)):
    # x is the index not the value, if you do want the value, you need to call the obj[x]
    print(f'Index: {x} Value: {data[x]}')  # data[0] Bob, data[1] Joe, data[2] Mary

'''
# Ask the user what contact details to print
row = input("Record to print: ")
print(f"First Name: {data[int(row)]} Last Name: ")
'''

print("---------")
## Pythonic using the in keyword with data set
## the in keyword handles the len() AND the range()
for x in data:
    # x is the value not the index
    print(x)  # x Bob,Joe,Mary
print("===== End of List Comprehension Example =====")

print("===== EAFP and LBYL Concepts =====")
# control variable
z = 'Bob'
# Python LBYL -> Look Before You Leap Principle
# if statements
print("===== LBYL Concept =====")
if z == 'Bob': # return True
    print("Do something with the true")
else: # return False
    print("Bob does not exist.")

# Pythonic EAFP -> Easier to Ask for Forgiveness than Permission Principle
# try except handlers
print("===== EAFP Concept =====")
try:
    if z == 'Bob':
        
        x = 9
        y = 0
        z = x / y # divide by zero error Exception -> except
    
        print("stuff here...")

    # do cleanup here, it wont run with Exit Code 1

except Exception as err:
    print(err)

# finally is optional, but highly recommend
finally: # all the time try or except
    print("finally -> Do all our cleanup here...")
    # GC, close db conn, close() .txt, security checks, write log files
    # final processes

print("===== End of EAFP and LBYL Concepts =====")

print("===== Context and Connection Management =====")
# IO reference
filename = 'process_logging.txt'

# Python Syntax -> Manually close IO's, commonly because you DO NOT use a keyword to open a connection (ex: with keyword)
# varname = open(io)
txtfile = open(filename, 'r')
content = txtfile.read()
print(content)
txtfile.close()

print("----")

# Pythonic -> utilize opening IO's with keywords. Connections automatically close when you get an exit code
# with open(io) as namespace
with open(filename, 'r') as f:
    content = f.read()
    print(content)
    # no need to close() handled by the with keyword

print("===== End of Context and Connection Management =====")

print("===== Regular Expressions are Pythonic =====")
# Python syntax .contains()
# regex101.com
# pattern matching or data validation
# Ask a user to enter there phone number
phone_number = input("Enter your phone number <ex. (xxx) xxx-xxxx>: ")

import re # Standard Library Python
# variable to hold our pattern   (555) 555-1212
pattern_phone = r"[(][1-9]\d{2}[)] \d{3}-\d{4}" # regexlib.com
# variable to search and return boolean
match = re.search(pattern_phone, phone_number) # boolean True or False

if match:
    print("Valid phone number")
else:
    print("invalid phone number. please enter as (###) ###-####")