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lists.py
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# side effects
a = [1,2,3]
b = a
a # [1, 2, 3]
b # [1, 2, 3]
id(a) # 2821206455232
id(b) # 2821206455232
c = [a, b]
c # [[1, 2, 3], [1, 2, 3]]
a.append(5)
c # [[1, 2, 3, 5], [1, 2, 3, 5]]
# no side effects
a = [1,2,3]
b = a
id(a) # 2821206706688
id(b) # 2821206706688
c = list(a)
a # [1, 2, 3]
b # [1, 2, 3]
c # [1, 2, 3]
id(a) # 2821206706688
id(c) # 2821206707264
d = a[::]
d # [1, 2, 3]
id(d) # 2821206444480
# List comprehension
my_list = list(range(100)) # range is not inclusive 0 - 99
my_list # [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99]
double = [i * 2 for i in my_list ]
double # [0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198]
pairs = [i for i in my_list if i % 2 == 0]
pairs # [0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98]