# Create a empty list using '[]' brackets
some_list = []
# or using the list() function
some_list = list()

# Initialize a list with items inside '[]' brackets
my_list = [1, 1, 3, "a", "cab boy", 4.0]

my_list = [23, 65, 12, 76, 10]
print(my_list)  # [23, 65, 12, 76, 10]

## Adding/Appending: Adding values to list
my_var = 1
my_list.append(my_var)
print(my_list)  # [23, 65, 12, 76, 10, 1]


## Altering: Change values of list items using indexes
my_list[0] = 100  # 1st element
my_list[4] = 200  # 5th element
print(my_list)  # [100, 65, 12, 76, 200, 1]


## Removing: Remove values from list
# eg remove 'my_var' from 'my_list'
my_list.remove(my_var)
print(my_list)  # [23, 65, 12, 76, 200]

# remove using 'del' statement is mostly preferred, eg 'del my_list[index]'
del my_list[0]  
# or even with slicing, eg 'del my_list[start_index:end_index]'
# or using 'pop()' method of list, eg 'my_list.pop(index)'
# Note: 'del' statement can be used to delete any other object too.
print(my_list)  # [65, 12, 76, 200]


## Checking if some value is present in list
if 20 in my_list:  # similar to "if some_var in my_list:" where "some_var = 20"
  print("not printed")
if 200 in my_list:
  print("printed") # printed

## Joining: Join two or more lists
# using '+' operator
my_list1 = [2, 4, 5, 6] + [34, 7, 4, 2]
print(my_list1)  # [2, 4, 5, 6, 34, 7, 4, 2]

# using 'extend()' method
my_list1.extend([3, 6, 2])
print(my_list1)  # [2, 4, 5, 6, 34, 7, 4, 2, 3, 6, 2]


## Multiplying: Multiply a list using '*' operator
eg_list = ["This", 30]
print(eg_list * 3)  # ['This', 30, 'This', 30, 'This', 30]

my_list = [1, 1, 3, "a", "cab boy", 4.0]
my_list1 = [45, 23, 5, 6, 34, 6, 22]

## Indexing: For accessing/altering elements
# as usual index 0 is the first element
var_1 = my_list1[0]
var_2 = my_list1[1]
print(var_1, var_2)  # 45, 23

# altering values in list, like we saw above
my_list1[0] = 100
my_list1[-1] = 200


## Iterating: Going over item by item from a list
for var in my_list1:
  print(var)  # [100, 23, 5, 6, 34, 6, 200]


## Slicing: For creating sub-list, syntax is [start_index:end_index:step]
print(my_list[3:5])  # ['a', 'cab boy']
print(my_list[5:])  # [4.0]
print(my_list[:3])  # [1, 1, 3]
print(my_list[:5:2])  # [1, 3, 'cab boy']
# negative indexing similar to string
print(my_list[:-4])  # [1, 1]
# reverse a list
print(my_list[::-1])  # [4.0, 'cab boy', 'a', 3, 1, 1]

## List comprehension: Create a new list in a single line
# Note: 'range()' function creates a sequence of integers,
# we'll learn more on range later
my_list1 = [x for x in range(10)]
# this is similar to
my_list1 = []
for x in range(10):
  my_list1.append(x)

# comprehensions are syntactic sugar, they save lines of code
# Nesting a list comprehension
my_list2 = [[y for y in range(x)] for x in range(5)]
# Adding if..else conditions
my_list3 = [abc for abc in range(10) if abc > 5]
my_list4 = [True if z > 5 else False for z in range(10)]
# Notice: The syntax difference between if and if..else clauses
# also try printing each of the list

my_list = [1, 2, 3, 4, 5, 6]
new_copy = my_list
del new_copy[0]  # deleting first item

print(my_list, new_copy)  # [2, 3, 4, 5, 6] [2, 3, 4, 5, 6]
# the deletion is reflected to 'my_list' too, because they refer to same object
# this behaviour is exclusive to mutable objects, this was the catch from
# 'Multiple Target assignment', modifications on mutable objects
# reflect changes to its references too


## Creating a copy
# Using colon in brackets or using "my_list.copy()"
new_copy = my_list[:]
# now they do not refer to the same object
print(id(new_copy), id(my_list))  # 1882455764160 1882447248640
del new_copy[0]
print(my_list, new_copy)  # [2, 3, 4, 5, 6] [3, 4, 5, 6]

my_list1 = [10, 50, 40, 50, 60, 80, 15]
# Reverse a list, its inplace so does not return anything
my_list1.reverse()
print(my_list1)  # [15, 80, 60, 50, 40, 50, 10]
# Sort a list, also inplace
my_list1.sort()
print(my_list1)  # [10, 15, 40, 50, 50, 60, 80]
# Return index of first arrival of a given value
print(my_list1.index(50))  # 3
# Remove a given value from list
my_list1.remove(15)
# Remove a value given a index from list, also returns the value
print(my_list1.pop(5))  # 80
# Empty a list
my_list1.clear()
print(my_list1)  # []

my_list1 = [10, 50, 40, 50, 60, 80, 15]

# Return a sorted list of items, ascending order by default
# sorting time complexity is O(nLogn)
print(sorted(my_list1))  # [10, 15, 40, 50, 50, 60, 80]
# for reversing just pass 'reverse=True'
print(sorted(my_list1, reverse=True))  # [80, 60, 50, 50, 40, 15, 10]

# Return the length of list
print(len(my_list1))  # 7

# Return the sum of items
print(sum(my_list1))  # 305
print(sum([10, 20]))  # 30

my_list = list((1, 2, 3, 4, 5))  # tuple to list
my_list = list({1, 2, 3, 4, 5})  # set to list

import sys
import array

# Create a normal list
my_list = [54, 32, 65, 32, 65, 32]
# the first parameter is c data type (only the ones mentioned in the table)
# and second is the data from a sequence type such as list/tuple
my_array = array.array("i", my_list)
print(my_array)  # array('i', [54, 32, 65, 32, 65, 32])
# 'i' stands for signed integer data type

# create a character data array
char_array = array.array("u", "somestr")
print(char_array)  # array('u', 'somestr')

# check their memory usage
print(sys.getsizeof(my_list))  # 152
print(sys.getsizeof(my_array))  # 88
# we can see the difference in bytes, array consumes less space compared to list

import array
my_array = array.array("i", [5, 7, 11, 6, 2, 8, 1])

## Indexing
print(my_array[0])  # 5


## Iterating
for a in my_array:
  print(a)  # [5,7,11,6,2,8,1]


## Slicing
print(my_array[1:3])  # array('i', [7, 11])

import array
my_array = array.array("i", [5, 3, 5, 5, 2, 7, 8])

my_array.append(30)
print(my_array.index(30))  # 7
my_array.remove(30)
print(my_array.pop(3))  # 5
# extending from array
my_array.fromlist([67, 87])
print(my_array)  # array('i', [5, 3, 5, 2, 7, 8, 67, 87])