Список, часть 2

1.7.1.py

# -*- encoding: utf-8 -*-
"""
Двумерный список
"""

matrix = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]

print matrix[1]
[4, 5, 6]

print matrix[1][1]

print matrix[2][0]

1.7.2.py

# -*- encoding: utf-8 -*-
"""
Конкатенация списков
"""

num_list = [43, -1.23, -2, 6.19e5]
str_list = ['jack', 'jumped', 'over', 'candlestick']
mixup_list = [4.0, [1, 'x'], 'beef', -1.9+6j]

print num_list + mixup_list
print str_list + num_list

1.7.3.py

# -*- encoding: utf-8 -*-
"""
Сравнение списков
"""

L1 = [1, ('a', 3)]         # same value, unique objects
L2 = [1, ('a', 3)]
print L1 == L2, L1 is L2         # equivalent?, same object?

1.7.4.py

# -*- encoding: utf-8 -*-
"""
Генератор списка
"""

li = ["a", "mpilgrim", "foo", "b", "c", "b", "d", "d"] 

print [elem for elem in li if len(elem) > 1]            

print [elem for elem in li if elem != "b"]               

print [elem for elem in li if li.count(elem) == 1]   

1.7.5.py

# -*- encoding: utf-8 -*-
"""
Генератор списка (расширенный пример)
"""

# List comprehensions provide a concise way to create lists without resorting to use 
# of map(), filter() and/or lambda. 

freshfruit = ['  banana', '  loganberry ', 'passion fruit  ']
print [weapon.strip() for weapon in freshfruit]

vec = [2, 4, 6]
print [3*x for x in vec]

print [3*x for x in vec if x > 3]

print [3*x for x in vec if x < 2]

print [[x,x**2] for x in vec]

print [(x, x**2) for x in vec]

vec1 = [2, 4, 6]
vec2 = [4, 3, -9]

print [x*y for x in vec1 for y in vec2]

print [x+y for x in vec1 for y in vec2]

print [vec1[i]*vec2[i] for i in range(len(vec1))]

print [str(round(355/113.0, i)) for i in range(1,6)]