Python基础学习(七) ------ 元组 / 列表
一.元组
叫做 tuple
,用小括号、或者无括号来表述,是一连串有顺序的数字。
a_tuple = (12, 3, 5, 15 , 6)
another_tuple = 12, 3, 5, 15 , 6
二.列表
而list
是以中括号来命名的:
a_list = [12, 3, 67, 7, 82]
遍历示例:
他们的元素可以一个一个地被迭代、输出、运用、定位取值:
for content in a_list:
print(content)
"""
12
3
67
7
82
"""
for content_tuple in a_tuple:
print(content_tuple)
"""
12
3
5
15
6
"""
下一个例子,依次输出a_tuple
和a_list
中的各个元素:
for index in range(len(a_list)):
print("index = ", index, ", number in list = ", a_list[index])
"""
index = 0 , number in list = 12
index = 1 , number in list = 3
index = 2 , number in list = 67
index = 3 , number in list = 7
index = 4 , number in list = 82
"""
for index in range(len(a_tuple)):
print("index = ", index, ", number in tuple = ", a_tuple[index])
"""
index = 0 , number in tuple = 12
index = 1 , number in tuple = 3
index = 2 , number in tuple = 5
index = 3 , number in tuple = 15
index = 4 , number in tuple = 6
"""
三.列表操作
1.添加(append / insert)
a = [1,2,3,4,1,1,-1]
a.append(0) # 在a的最后面追加一个0
print(a)
# [1, 2, 3, 4, 1, 1, -1, 0]
a = [1,2,3,4,1,1,-1]
a.insert(1,0) # 在位置1处添加0,可指定位置
print(a)
# [1, 0, 2, 3, 4, 1, 1, -1]
2.移除(remove)
a = [1,2,3,4,1,1,-1]
a.remove(2) # 删除列表中第一个出现的值为2的项
print(a)
# [1, 3, 4, 1, 1, -1]
3.索引
显示特定位( [] ):
a = [1,2,3,4,1,1,-1]
print(a[0]) # 显示列表a的第0位的值
# 1
print(a[-1]) # 显示列表a的最末位的值
# -1
print(a[0:3]) # 显示列表a的从第0位 到 第2位(第3位之前) 的所有项的值
# [1, 2, 3]
print(a[5:]) # 显示列表a的第5位及以后的所有项的值
# [1, -1]
print(a[-3:]) # 显示列表a的倒数第3位及以后的所有项的值
# [1, 1, -1]
打印列表中的某个值的索引(.index):
a = [1,2,3,4,1,1,-1]
print(a.index(2)) # 显示列表a中第一次出现的值为2的项的索引
# 1
统计列表中某值出现的次数(.count):
a = [4,1,2,3,4,1,1,-1]
print(a.count(-1))
# 1