{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# 成员运算"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<font size=\"4\">运算符 in 和 not in 用于成员检测，返回布尔值True 或 False。如果 x 是 s 的成员则 x in s 值为 True，否则为 False。 x not in s 返回 x in s 取反后的值。所有内置序列和集合类型以及字典都支持此运算，对于字典来说 in 检测其是否在字典的键中存在。\n",
"对于字符串和字节串类型来说，当且仅当 x 是 y 的子串时 x in y 为 True。空字符串总是被视为任何其他字符串的子串，因此 \"\" in \"abc\" 将返回 True。成员运算符的描述如表 2.2 所示。</font>"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"| 运算符 | 描述 | 实例 |\n",
"| :------ | :--------- | :------------ |\n",
"| in | 如果对象在某一个序列中存在，返回 True，否则返回 False | print('u' in ['U','u','USD']) # 输出 True |\n",
"| not in |如果对象在某一个序列中不存在，返回 True，否则返回 False | print('r' not in ['U','u','USD']) # 输出True |"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"Python 中的成员运算使用语法是："
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [],
"source": [
"obj [not] in sequence"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"+ ##### `x in s` ：如果 x <font color=Red>__是__</font> s 的<font color=Red>__成员__</font>则返回值值为True，否则为False。 \n",
"\n",
"+ ##### `x not in s` ：如果 x <font color=Red>__不是__</font> s 的<font color=Red>__成员__</font>则返回值为True，否则为False。即返回x in s 取反后的值。\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"s 可以是字符串，列表、元组、range、字典的键、集合等。\n",
"+ 对于字符串和字节串类型来说，当且仅当x 是y 的<font color=Red>__子串__</font>时，`x in y` 为True"
]
},
{
"cell_type": "code",
"execution_count": 1,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"True\n",
"False\n",
"False\n"
]
}
],
"source": [
"print('admin' in 'administrator') # True\n",
"print('ada' in 'administrator') # False\n",
"print(' ' in 'admin') # False，空格字符串"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<font size=\"4\"><font color=Red>__空字符串__</font>总是被视为任何其他字符串的<font color=Red>__子串__</font>。</font>"
]
},
{
"cell_type": "code",
"execution_count": 3,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"True\n",
"False\n",
"0\n",
"1\n",
"2\n",
"3\n",
"4\n",
"5\n",
"6\n",
"7\n",
"8\n",
"9\n"
]
}
],
"source": [
"print('' in 'admin') # True，空字符串\n",
"print(' ' in 'admin') # False，空格字符串\n",
"\n",
"for i in range(10):\n",
" print(i)\n",
" \n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"+ ### 所有内置序列、集合类型、字典都支持<font color=Red>__成员运算__</font>，测试元素 x 是否为对象 s 的一个成员（元素）。\n"
]
},
{
"cell_type": "code",
"execution_count": 4,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"True\n",
"True\n",
"False\n",
"True\n",
"False\n"
]
}
],
"source": [
"print(10 in range(1, 20)) # True，range(1,20)生成的数据中包含10\n",
"print('me' in {'you', 'me', 'he'}) # True，字符串'me'为集合中的一个元素\n",
"print('she' in {'you', 'me', 'he'}) # False，集合元素中不包含字符串'she'\n",
"print(2 in [1, 2, 3, 4, 5]) # True，整数2为列表中的一个元素\n",
"print(6 in (1, 2, 3, 4, 5)) # False，元组元素中不包含整数6"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<font size=\"4\">注意下面两种情况的区别。</font>"
]
},
{
"cell_type": "code",
"execution_count": 5,
"metadata": {},
"outputs": [],
"source": [
"print([1, 2] in [[1, 1], [1, 2], [1, 3]]) # True，列表[1, 2]为后面列表中的一个元素\n",
"print([1, 2] in [1, 2, 3, 4, 5]) # False，后面的列表中所有元素均为整数，并不包含列表1, 2]"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<font size=\"4\">对于字典来说成员运算检测对象是否在<font color=Red>__字典的键__</font>中存在。</font>"
]
},
{
"cell_type": "code",
"execution_count": 6,
"metadata": {},
"outputs": [],
"source": [
"print('me' in {'you': 100, 'me': 1000, 'he': 50}) # True\n",
"print(100 in {'you': 100, 'me': 1000, 'he': 50}) # False"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"### 实例2.2 判断字符类型"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"输入一个字符，判断这个字符是小写字母还是数字。\n",
"判定一个字符的类型，可以用成员运算，用in检测目标是否在对应的字符集中存在，若目标在所有字母构成的字符串中存在则该字符是字母，若目标在所有数字构成的字符串中存在，则该字符是数字字符。"
]
},
{
"cell_type": "code",
"execution_count": 7,
"metadata": {},
"outputs": [],
"source": [
"letter = input() # 输入一个字符\n",
"ascii_letters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ' # 所有字母\n",
"if letter in ascii_letters: # 成员检测，输入字符在字母字符串中存在时\n",
" print('这是字母') # 输出'这是字母'\n",
"if letter in '0123456789': # 成员检测，输入字符在数字字符串中存在时\n",
" print('这是数字') # 输出'这是数字'"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<font face='楷体' color='red' size=5> 练一练 </font>\n",
"\n",
"##### 完成下面的程序，判断输入的字符是否为元音字母（大小写不限）。\n",
"\n",
"用户输入一个字符，若该字符为英文元音字母，则输出'这是元音字母'；否则输出'这不是元音字母'。\n",
"\n",
"**输入输出样例：**\n",
"\n",
" 输入：a\n",
" 输出：这是元音字母\n",
"\n",
" 输入：Q\n",
" 输出：这不是元音字母\n",
"\n",
"**提示**：考虑大小写，元音字母包括A、E、I、O、U、a、e、i、o、u"
]
},
{
"cell_type": "code",
"execution_count": 7,
"metadata": {},
"outputs": [],
"source": [
"c = input()\n",
"# 参考前面的实例，补充代码，判断输入的c是否为元音字母\n",
"\n",
"\n",
"\n",
"\n"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [],
"source": [
"测试输出：\n",
"A\n",
"字母A是元音字母\n",
"i\n",
"字母i是元音字母\n",
"z\n",
"字母z不是元音字母"
]
}
],
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