分享程序员开发的那些事...
更新时间：2022-06-14 23:03:29
说明：
Python中的列表类似于其它高级语言中的数组，不过Python的列表操作起来要轻松很多。
Python中列表的学习主线主要是围绕对列表参数的操作使用上，重点关注的应该有如下这些：
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names.append(names.count(names.extend(names.index(names.insert(names.pop(names.remove(names.reverse(names.sort( |
下面的内容基本上都是围绕上面的操作进行说明。
1.基本操作
·基本的操作主要有如下：
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names[num]：排序为数字num的元素names[-1:]：最后1个元素
names[-5:]：最后5个元素
names[-5:-1]：最后5个元素，但不包括最后1个元素（即不包括names[-1]）
names[:5]：开始5个元素（即不包括names[5]）
names[0:5]：开始5个元素（即不包括names[5]）
names[10:15]：names[10]到names[14]
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·上面有取范围的情况，前后两个数字，可以记为：“虎头蛇尾”，即取前不取后
· 以下面的环境做一个简单的测试：
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>>> names = ['xpleaf','yonghaoyip','CL']
>>> names.extend(range(30))
>>> names['xpleaf', 'yonghaoyip', 'CL', 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]
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(1）names[num]：排序为数字num的元素
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>>> names[2]
'CL' |
（2）names[-1：]：最后1个元素
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>>> names[-1:]
[29]
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（3）names[-5:]：最后5个元素
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>>> names[-5:]
[25, 26, 27, 28, 29]
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（4）names[-5:-1]：最后5个元素，但不包括最后1个元素（即不包括names[-1]）
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>>> names[-5:-1]
[25, 26, 27, 28]
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（5）names[:5]或names[0:5]：开始5个元素（即不包括names[5]）
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>>> names[:5]
['xpleaf', 'yonghaoyip', 'CL', 0, 1]
>>> names[0:5]
['xpleaf', 'yonghaoyip', 'CL', 0, 1]
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（6）names[10:15]：names[10]到names[14]
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>>> names[10:15]
[7, 8, 9, 10, 11]
>>> names[10]
7>>> names[14]
11>>> names[15]
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2.append()参数
·基本功能：向列表中添加元素
·基本语法：
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names.append('xpleaf')
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·append()参数在列表的最后面增加元素，一次只能添加一个；
·演示如下：
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>>> names.append('xpleaf')
>>> names['xpleaf', 'yonghaoyip', 'CL', 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, 'xpleaf']
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3.count()参数
·基本功能：计算列表中相同元素的个数
·基本语法：
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names.count('xpleaf')
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·演示如下：
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>>> names['xpleaf', 'yonghaoyip', 'CL', 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, 'xpleaf']
>>> names.count('xpleaf')
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·进阶演示：count()可以比较字符串中是否含有包含的字符串
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>>> name = 'xpleaf'
>>> name.count('xp')
1>>> name.count('leaf')
1>>> name.count('xpleaf123')
0===>如果包含有查找的字符串，则返回1，否则返回0
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4.extend()参数
·基本功能：将另一个列表中的元素合并到当前列表中
·基本语法：
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names.extend(range(10))
等价于下面的内容：names = names + range(10) ===>列表也可以直接做加法，Python中序列的特性
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·演示如下：
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>>> names['xpleaf', 'yonghaoyip', 'CL', 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, 'xpleaf']
>>> range(10) ===>range()的输出本来就是一个列表
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> names.extend(range(10))
>>> names['xpleaf', 'yonghaoyip', 'CL', 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, 'xpleaf', 0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
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·append()添加的是列表中的元素，如果写成下面这样：
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names.append(range(10))
===>只会在names列表末尾处添加一个列表元素[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
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5.index()参数
·基本功能：找出需要查找的列表元素的索引号
·基本语法：
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names.index('xpleaf')
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·如果列表中有多个相同元素，index()找出的只是第1个相同元素的索引号
·演示如下：
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>>> names.append('CL')
>>> names['xpleaf', 'yonghaoyip', 'CL', 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, 'xpleaf', 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 'CL']
>>> names.index('xpleaf')
0>>> names.index('CL')
2>>> names[2]
'CL' |
6.inset()参数
·基本功能：在列表中某一位置插入元素
·基本语法：
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names.insert(6,'love') ===>在列表的索引号为6的位置中插入元素'love'
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·演示如下：
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>>> names['xpleaf', 'yonghaoyip', 'CL', 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, 'xpleaf', 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 'CL']
>>> names.insert(6,'love')
>>> names['xpleaf', 'yonghaoyip', 'CL', 0, 1, 2, 'love', 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, 'xpleaf', 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 'CL']
>>> names[6]
'love' |
--小的综合操作：将上面列表中的'xpleaf'替换为'xpleaf_Yip'
·未充分利用Python特性的笨方法：
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>>> while True:
... if names.count('xpleaf') == 0:
... break
... else:
... names[names.index('xpleaf')] = 'xpleaf_Yip'
... >>> names['xpleaf_Yip', 'yonghaoyip', 'CL', 0, 1, 2, 'love', 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, 'xpleaf_Yip', 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 'CL']
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·虽然可以达到目的，但实际上该方法是比较笨的；
·充分利用Python特性的方法：
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>>> for i in range(names.count('xpleaf')):
... names[names.index('xpleaf')] = 'xpleaf_Yip'
... >>> names['xpleaf_Yip', 'yonghaoyip', 'CL', 0, 1, 2, 'love', 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, 'xpleaf_Yip', 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 'CL']
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7.pop()参数
·基本功能：将列表中最后一个元素删除
·基本语法：
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names.pop() |
·演示如下：
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>>> names['xpleaf_Yip', 'yonghaoyip', 'CL', 0, 1, 2, 'love', 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, 'xpleaf_Yip', 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 'CL']
>>> names.pop()'CL'>>> names['xpleaf_Yip', 'yonghaoyip', 'CL', 0, 1, 2, 'love', 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, 'xpleaf_Yip', 0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
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8.remove()参数
·基本功能：删除列表中指定内容的元素
·基本语法：
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names.remove('love') ===>删除列表中'love'元素
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·演示如下：
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>>> names['xpleaf_Yip', 'yonghaoyip', 'CL', 0, 1, 2, 'love', 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, 'xpleaf_Yip', 0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> names.remove('love')
>>> names['xpleaf_Yip', 'yonghaoyip', 'CL', 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, 'xpleaf_Yip', 0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
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·如果存在多个相同的元素，则只删除第1个：
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>>> names.remove(0)
>>> names['xpleaf_Yip', 'yonghaoyip', 'CL', 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, 'xpleaf_Yip', 0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
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9.sort()参数
·基本功能：以ASCII表的顺序对列表中的元素进行排序，纯数值元素会在前面
·基本语法：
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names.sort() |
·演示如下：
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>>> names.sort()>>> names[0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 'CL', 'xpleaf_Yip', 'xpleaf_Yip', 'yonghaoyip']
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·如果有多个元素的字符串，则按字符串中的字符依次顺序比较，直到有不相同的为止；
10.reverse()参数
·基本功能：将原来列表中的元素倒序存储
·基本语法：
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names.reverse() |
·演示如下：
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>>> names.reverse()>>> names['yonghaoyip', 'xpleaf_Yip', 'xpleaf_Yip', 'CL', 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 9, 8, 8, 7, 7, 6, 6, 5, 5, 4, 4, 3, 3, 2, 2, 1, 1, 0]
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11.与列表相关的其它操作
--删除列表中的元素：del
·不用remove()的方式删除，需要指定索引号；
·演示如下：
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>>> names['yonghaoyip', 'xpleaf_Yip', 'xpleaf_Yip', 'CL', 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 9, 8, 8, 7, 7, 6, 6, 5, 5, 4, 4, 3, 3, 2, 2, 1, 1, 0]
>>> names[2]
'xpleaf_Yip'>>> del names[2]
>>> names['yonghaoyip', 'xpleaf_Yip', 'CL', 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 9, 8, 8, 7, 7, 6, 6, 5, 5, 4, 4, 3, 3, 2, 2, 1, 1, 0]
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--将字符串内容变为列表中的元素：list()
·演示如下：
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>>> import string
>>> string.ascii_lowercase'abcdefghijklmnopqrstuvwxyz'>>> a = list(string.ascii_lowercase)>>> a['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
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--将列表中的元素连接为字符串：''.join()
·str()只会将整个列表作为一个字符串：
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>>> str(a)"['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']" |
·把列表元素连接成字符串方法如下：
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>>> ''.join(a)
'abcdefghijklmnopqrstuvwxyz'>>> '_'.join(a)
'a_b_c_d_e_f_g_h_i_j_k_l_m_n_o_p_q_r_s_t_u_v_w_x_y_z' |
·''.join()参数中的列表元素只能是字符串型，不能是数值型：
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>>> str(names)"['yonghaoyip', 'xpleaf_Yip', 'CL', 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 9, 8, 8, 7, 7, 6, 6, 5, 5, 4, 4, 3, 3, 2, 2, 1, 1, 0]">>> ''.join(names)
Traceback (most recent call last): File "<stdin>", line 1, in <module>
TypeError: sequence item 3: expected string, int found
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12.元组的提及
·元组跟列表一样，但元组内容一旦生成，无法修改；
·元组主要是用来存储别人不能修改的内容；
·元组的相关操作演示和说明如下：
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>>> tuple = ('a', 'b', 'c', 1, 2, 3)
>>> tuple('a', 'b', 'c', 1, 2, 3)
>>> tuple[3] ===>取特定一个元素时，与列表类似
1>>> tuple[3] = 'b' ===>不能修改元组的元素内容
Traceback (most recent call last): File "<stdin>", line 1, in <module>
TypeError: 'tuple' object does not support item assignment
>>> del tuple[3] ===>也不能删除元组中的某一元素
Traceback (most recent call last): File "<stdin>", line 1, in <module>
TypeError: 'tuple' object doesn't support item deletion
>>> list(tuple)['a', 'b', 'c', 1, 2, 3]
>>> tuple. ===>按tab键后可以看到只有count()和index（）参数与列表相似……tuple.count(tuple.index( |
·将元组变为列表时可使用list()函数。