{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# 字符串遍历"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "字符串的遍历是指用循环的方法依次获取字符串中的每个字符"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "for c in string:        # 变量c依次取值为字符串中的字符\n",
    "    语句块"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "string为字符串  \n",
    "循环次数为字符串中字符个数  \n",
    "变量c依次被赋值为字符串中的字符"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "输入一个字符串，逐行输出其中的字符。(竖向输出一个字符串)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [
    {
     "name": "stdin",
     "output_type": "stream",
     "text": [
      " nanning\n"
     ]
    },
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "n\n",
      "a\n",
      "n\n",
      "n\n",
      "i\n",
      "n\n",
      "g\n"
     ]
    }
   ],
   "source": [
    "my_string = input()  # 输入一个字符串\n",
    "for c in my_string:  # 遍历，c依次取值为字符串中的字符\n",
    "    print(c)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 实例6.8 分类统计字符个数 "
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "输入一个字符串，统计字符串里英文字母、数字和其他字符的个数。"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "name": "stdin",
     "output_type": "stream",
     "text": [
      " jkgkdgh230那个经理\n"
     ]
    },
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "字母7个, 数字3个, 其他字符4个\n"
     ]
    }
   ],
   "source": [
    "import string                      # 导入string库，使用库中字符会串常量\n",
    " \n",
    "my_string = input()                # 输入一个字符串\n",
    "letter, digit, other = 0, 0, 0     # 用于计数的3个变量均设初值为0\n",
    "for c in my_string:                # 遍历，c依次取值为字符串中的字符\n",
    "    if c in string.ascii_letters:  # 若c在字母常量中存在，则c是字母\n",
    "        letter = letter + 1        # 字母计数加1个\n",
    "    elif c in string.digits:       # 若c在数字常量中存在，则c是数字\n",
    "        digit = digit + 1          # 数字计数加1个\n",
    "    else:\n",
    "        other = other + 1          # 否则其他字符计数加1个\n",
    "print(f\"字母{letter}个, 数字{digit}个, 其他字符{other}个\")\n",
    "# 123 The operators in and not in test for membership 456.\n",
    "# 字母39个, 数字6个, 其他字符11个"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "my_string = input()                # 输入一个字符串\n",
    "letter, digit, other = 0, 0, 0     # 用于计数的3个变量均设初值为0\n",
    "for c in my_string:                # 遍历，c依次取值为字符串中的字符\n",
    "    if c in 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ' :  # 若c在字母常量中存在，则c是字母\n",
    "        letter = letter + 1        # 字母计数加1个\n",
    "    elif c in '0123456789':       # 若c在数字常量中存在，则c是数字\n",
    "        digit = digit + 1          # 数字计数加1个\n",
    "    else:\n",
    "        other = other + 1          # 否则其他字符计数加1个\n",
    "print(f\"字母{letter}个, 数字{digit}个, 其他字符{other}个\")\n",
    "# 123 The operators in and not in test for membership 456.\n",
    "# 字母39个, 数字6个, 其他字符11个"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
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