{ "cells": [ { "cell_type": "markdown", "id": "9571b890-f74b-47da-9d17-89fd797fa493", "metadata": {}, "source": [ "#### Jupyter Notebook 的基本操作\n", "\n", "- **创建新 Notebook**: 在 Jupyter 的主页上，点击右上角的 \"New\" 按钮，然后选择 \"Python 3\" 来创建一个新的 Notebook。\n", "\n", "- **运行单元格**: 选择一个单元格后，按 `Shift + Enter` 运行该单元格的内容。代码单元格会执行代码并显示输出。\n", "\n", "- **保存 Notebook**: 点击工具栏上的保存图标，或者使用快捷键 `Ctrl + S`（Windows）或 `Cmd + S`（macOS）。\n", "\n", "#### 注释的用法\n", "\n", "在编写代码时，注释是非常重要的，它们可以帮助你和其他人理解代码的目的和功能。注释不会被执行，只是作为说明存在。\n", "\n", "- **单行注释**: 使用 `#` 符号。所有在 `#` 后面的内容都会被视为注释。\n" ] }, { "cell_type": "code", "execution_count": 15, "id": "02f18fde-16d9-45af-b3df-308d3d8bd9eb", "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Hello, World!\n" ] } ], "source": [ "# 这是一个单行注释\n", "print(\"Hello, World!\") # 这也是一个注释" ] }, { "cell_type": "markdown", "id": "12b4e652-cb8b-4c2e-abb8-237b44dc1570", "metadata": {}, "source": [ "### 代码块\n", "\n", "在 Jupyter Notebook 中，代码块是指一个代码单元格，它可以包含一段或多段 Python 代码。每个代码块都是一个独立的执行单元，你可以在其中编写代码、运行代码，并查看输出结果。以下是关于代码块及其输入输出的详细解释：\n", "\n", "- **代码单元格**: 在 Jupyter Notebook 中，代码块通常指的是代码单元格。你可以在代码单元格中输入 Python 代码，并通过运行该单元格来执行代码。\n", "\n", "- **运行代码块**: 选择一个代码单元格后，按 `Shift + Enter` 或点击工具栏上的 \"Run\" 按钮来运行代码。运行后，代码的输出会显示在单元格下方。\n", "\n", "### 输入和输出\n", "\n", "- **输入（In）**: 在 Jupyter Notebook 中，每个代码单元格的左侧会显示一个标签，如 `In [1]:`。这个标签表示这是第几个被执行的输入单元格。输入是指你在代码单元格中编写的代码。\n", "\n", "- **输出（Out）**: 当你运行一个代码单元格时，代码的执行结果会显示在单元格下方，这就是输出。输出可以是任何 Python 表达式的结果，如数值、字符串、列表、图表等。\n", "\n", "#### 示例" ] }, { "cell_type": "markdown", "id": "d5bbfeb8-7507-47b6-8145-f9858462fd81", "metadata": {}, "source": [ "- **输入**: 上述代码块中的所有代码行。\n", "- **输出**: 运行代码块后，输出会显示为 `15`，这是最后一个表达式 `sum` 的结果。\n" ] }, { "cell_type": "code", "execution_count": 12, "id": "b1a5270e-036a-4949-9f16-a2309831eba5", "metadata": {}, "outputs": [ { "data": { "text/plain": [ "15" ] }, "execution_count": 12, "metadata": {}, "output_type": "execute_result" } ], "source": [ "# 这是一个简单的代码块\n", "a = 5\n", "b = 10\n", "sum = a + b\n", "sum # 这个表达式的结果会作为输出显示" ] }, { "cell_type": "markdown", "id": "a903b6a9-ca5c-4ddb-8d6e-b693e481ad6f", "metadata": {}, "source": [ "### 多个输出\n", "\n", "在一个代码单元格中，只有最后一个表达式的结果会被自动显示为输出。如果你想在一个单元格中显示多个输出，可以使用 `print()` 函数。" ] }, { "cell_type": "code", "execution_count": 14, "id": "c607e8f0-f191-40e1-bff0-6689f5e65639", "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "5\n", "10\n", "15\n" ] } ], "source": [ "# 显示多个输出\n", "print(a) # 输出 a 的值\n", "print(b) # 输出 b 的值\n", "print(sum) # 输出 sum 的值" ] }, { "cell_type": "markdown", "id": "5affaf61-f01d-43d8-b807-ed872d659563", "metadata": {}, "source": [ "---" ] }, { "cell_type": "markdown", "id": "7ef935bd-0289-48c7-aa49-36750d5dcda2", "metadata": {}, "source": [ "### 2. Python基础\n", "#### 2.1 变量和数据类型" ] }, { "cell_type": "code", "execution_count": 1, "id": "777ef098-4dd3-46ba-a642-45bc8eef3636", "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ " \n" ] } ], "source": [ "# 整数\n", "a = 10\n", "# 浮点数\n", "b = 20.5\n", "# 字符串\n", "c = \"Hello, World\"\n", "# 布尔值\n", "d = True\n", "\n", "print(type(a), type(b), type(c), type(d))" ] }, { "cell_type": "markdown", "id": "55fcc17d-8684-4cda-9df3-a2256e17f81f", "metadata": {}, "source": [ "#### 2.2 基本运算" ] }, { "cell_type": "code", "execution_count": 3, "id": "13f3fadf-e16b-4b4e-91af-630cbc0bdf98", "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "30.5 -10.5 205.0 0.4878048780487805\n" ] } ], "source": [ "# 算术运算\n", "sum = a + b\n", "difference = a - b\n", "product = a * b\n", "quotient = a / b\n", "\n", "print(sum, difference, product, quotient)" ] }, { "cell_type": "markdown", "id": "62d1f7f3-cdcf-4a1f-84aa-e12e39ce59ad", "metadata": {}, "source": [ "#### 2.3 列表 List\n", "\n", "列表（list）是一种非常常用的数据结构。它可以存储多个元素，并且这些元素可以是不同类型的。下面是一些常用的列表操作及其解释：" ] }, { "cell_type": "code", "execution_count": 28, "id": "b11a3e0c-4c4d-4d83-b231-cb57f841946f", "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "apple\n", "cherry\n" ] } ], "source": [ "# 创建列表\n", "fruits = [\"apple\", \"banana\", \"cherry\"]\n", "print(fruits[0]) # 访问第一个元素\n", "print(fruits[-1]) # 访问最后一个元素" ] }, { "cell_type": "markdown", "id": "8cd1edab-0c73-4c74-a81e-4ec3af3e5010", "metadata": {}, "source": [ "你可以使用 `append()` 方法在列表末尾添加元素" ] }, { "cell_type": "code", "execution_count": 29, "id": "8b65db8c-3013-4809-8027-8e543a9bd784", "metadata": {}, "outputs": [ { "data": { "text/plain": [ "['apple', 'banana', 'cherry', 'orange']" ] }, "execution_count": 29, "metadata": {}, "output_type": "execute_result" } ], "source": [ "# 在末尾添加一个元素\n", "fruits.append('orange')\n", "# 现在 fruits 是 ['apple', 'blueberry', 'cherry', 'orange']\n", "fruits" ] }, { "cell_type": "markdown", "id": "70032e23-b96b-46fb-bd6f-6d4caea1719d", "metadata": {}, "source": [ "你可以使用 `remove()` 方法删除指定的元素，或者使用 `pop()` 方法删除指定位置的元素（默认删除最后一个）。" ] }, { "cell_type": "code", "execution_count": 30, "id": "21e56204-b7c9-411f-8e54-3c55c9738e9c", "metadata": {}, "outputs": [ { "data": { "text/plain": [ "['apple', 'banana', 'cherry']" ] }, "execution_count": 30, "metadata": {}, "output_type": "execute_result" } ], "source": [ "# 删除最后一个元素\n", "last_fruit = fruits.pop()\n", "# 现在 fruits 是 ['apple', 'blueberry', 'cherry']\n", "fruits" ] }, { "cell_type": "code", "execution_count": 32, "id": "f4532754-3c89-40fa-bbe1-e52f47748a9b", "metadata": {}, "outputs": [ { "data": { "text/plain": [ "'orange'" ] }, "execution_count": 32, "metadata": {}, "output_type": "execute_result" } ], "source": [ "# last_fruit 是 'orange'\n", "last_fruit" ] }, { "cell_type": "markdown", "id": "474fd23f-e596-45c5-b400-c3d14826fc38", "metadata": {}, "source": [ "你可以使用 `sort()` 方法对列表进行排序。" ] }, { "cell_type": "code", "execution_count": 34, "id": "785754cf-a820-4558-a61b-7045127f8436", "metadata": {}, "outputs": [ { "data": { "text/plain": [ "[1, 1, 2, 3, 4, 5, 9]" ] }, "execution_count": 34, "metadata": {}, "output_type": "execute_result" } ], "source": [ "numbers = [3, 1, 4, 1, 5, 9, 2]\n", "numbers.sort()\n", "numbers" ] }, { "cell_type": "markdown", "id": "f4efda3a-7b00-42a1-bbda-76bc8bc59425", "metadata": {}, "source": [ "你可以使用切片操作来获取列表的一个子集。" ] }, { "cell_type": "code", "execution_count": 36, "id": "ced60078-2aaa-470c-8f65-4f03b8a9c5d4", "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "['apple', 'banana']\n", "['banana', 'cherry']\n" ] } ], "source": [ "# 获取第一个和第二个元素\n", "subset = fruits[0:2] # ['apple', 'cherry']\n", "print(subset)\n", "\n", "# 获取从第二个元素到最后的所有元素\n", "subset = fruits[1:] # ['cherry']\n", "print(subset)" ] }, { "cell_type": "markdown", "id": "d9e93e52-f799-4696-9c9f-d636075f50f2", "metadata": {}, "source": [ "#### 2.4 字典 Dict\n", "\n", "字典（dictionary）是一种用于存储键值对（key-value pairs）的数据结构。字典中的每个键都是唯一的，并且可以通过键快速访问对应的值。下面是一些常用的字典操作及其解释：\n" ] }, { "cell_type": "code", "execution_count": 37, "id": "6f7a187a-9b2d-4a39-aef3-8e0d22af5670", "metadata": {}, "outputs": [ { "data": { "text/plain": [ "25" ] }, "execution_count": 37, "metadata": {}, "output_type": "execute_result" } ], "source": [ "# 创建一个空字典\n", "my_dict = {}\n", "\n", "# 创建一个包含一些键值对的字典\n", "person = {'name': 'Alice', 'age': 25, 'city': 'New York'}\n", "\n", "# 访问键为 'name' 的值\n", "name = person['name'] # 'Alice'\n", "\n", "# 访问键为 'age' 的值\n", "person['age'] # 25" ] }, { "cell_type": "code", "execution_count": 38, "id": "1c053ace-6613-4046-a269-9400edf8b28b", "metadata": {}, "outputs": [ { "data": { "text/plain": [ "{'name': 'Alice', 'age': 25, 'city': 'New York', 'email': 'alice@example.com'}" ] }, "execution_count": 38, "metadata": {}, "output_type": "execute_result" } ], "source": [ "# 添加一个新的键值对\n", "person['email'] = 'alice@example.com'\n", "person" ] }, { "cell_type": "code", "execution_count": 39, "id": "426d7a12-f908-47f0-b4ec-c37104fe890d", "metadata": {}, "outputs": [ { "data": { "text/plain": [ "{'name': 'Alice', 'age': 25, 'email': 'alice@example.com'}" ] }, "execution_count": 39, "metadata": {}, "output_type": "execute_result" } ], "source": [ "# 删除键为 'city' 的键值对\n", "del person['city']\n", "person" ] }, { "cell_type": "code", "execution_count": 40, "id": "e56c8bb6-1cb9-4866-9eac-4cd9111be196", "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "True False\n" ] } ], "source": [ "# 检查 'name' 是否在字典中\n", "has_name = 'name' in person # True\n", "\n", "# 检查 'city' 是否在字典中\n", "has_city = 'city' in person # False\n", "print(has_name, has_city)" ] }, { "cell_type": "markdown", "id": "06d6079d-e554-4e65-ae86-026db05a94dd", "metadata": {}, "source": [ "### 3. 控制结构\n", "#### 3.1 条件语句" ] }, { "cell_type": "code", "execution_count": 5, "id": "4e1b439a-59d2-4786-9d8e-78f0139a8782", "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "a is less than or equal to b\n" ] } ], "source": [ "if a > b:\n", " print(\"a is greater than b\")\n", "else:\n", " print(\"a is less than or equal to b\")" ] }, { "cell_type": "markdown", "id": "d3c4da0f-69dd-4c5b-8296-5203cc3ced2b", "metadata": {}, "source": [ "### 4. 函数" ] }, { "cell_type": "code", "execution_count": 6, "id": "0a404d8d-b5f5-409e-924a-b6f644c9e64d", "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Hello, Alice!\n" ] } ], "source": [ "def greet(name):\n", " return f\"Hello, {name}!\"\n", "\n", "print(greet(\"Alice\"))" ] }, { "cell_type": "markdown", "id": "8014998b-9966-4211-a73b-2630783a26de", "metadata": {}, "source": [ "### 5. 文本处理\n", "#### 5.1 字符串操作\n", "\n", "Python提供了许多内置的方法来操作字符串。在这段代码中，我们使用了 `split()` 方法。`split()` 是一个字符串方法，用于将字符串拆分为子字符串**列表**。默认情况下，它会在空白字符（如空格、制表符、换行符等）处分割字符串。\n", "\n", "列表是Python中的一种数据结构，用于存储有序的元素集合。列表中的元素可以是任何数据类型，并且列表是可变的（即可以修改）。在这段代码中，`words = text.split()` 将返回一个列表，其中包含字符串 `text` 中的每个单词作为列表的元素。" ] }, { "cell_type": "code", "execution_count": 7, "id": "12593239-b389-4081-a00f-f462fafc9b68", "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "['Python', 'is', 'great', 'for', 'text', 'processing']\n" ] } ], "source": [ "text = \"Python is great for text processing\"\n", "words = text.split()\n", "print(words)" ] }, { "cell_type": "markdown", "id": "3f2a12b5-746b-45cf-9d41-62c129a6399f", "metadata": {}, "source": [ "#### 5.2 字符串拼接\n", "\n", "在这段代码中，我们展示了几种在Python中处理和格式化字符串的常用方法：\n", "\n", "1. **字符串拼接**：\n", " - 使用加号 (`+`) 进行字符串拼接是最基本的方法。它将多个字符串连接在一起形成一个新的字符串。在示例中，`greeting`、`name` 和其他字符串通过加号连接，形成完整的问候语 `Hello, Alice!`。\n", "\n", "2. **`join` 方法**：\n", " - `join` 是一个字符串方法，用于将一个可迭代对象（如列表或元组）中的元素连接成一个字符串。每个元素之间用调用 `join` 的字符串作为分隔符。在示例中，`\" \".join(words)` 将列表 `words` 中的元素用空格连接，形成句子 `Python is fun`。\n", "\n", "3. **f-string（格式化字符串）**：\n", " - f-string 是Python 3.6引入的一种字符串格式化方法。它通过在字符串前加上字母 `f`，并在字符串中使用大括号 `{}` 包含变量名或表达式，来实现字符串的动态插值。在示例中，`f\"My name is {name} and I am {age} years old.\"` 使用了 f-string，将变量 `name` 和 `age` 的值插入到字符串中，生成 `My name is Alice and I am 24 years old.`。" ] }, { "cell_type": "code", "execution_count": 22, "id": "bc287103-f8bc-4c8e-8255-f5dfc679fc05", "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Hello, Alice!\n", "Python is fun\n", "My name is Alice and I am 24 years old.\n" ] } ], "source": [ "# 使用加号拼接字符串\n", "greeting = \"Hello\"\n", "name = \"Alice\"\n", "message = greeting + \", \" + name + \"!\"\n", "print(message)\n", "\n", "# 使用join方法\n", "words = [\"Python\", \"is\", \"fun\"]\n", "sentence = \" \".join(words)\n", "print(sentence)\n", "\n", "name = \"Alice\"\n", "age = 24\n", "\n", "# 使用f-string\n", "formatted_text = f\"My name is {name} and I am {age} years old.\"\n", "print(formatted_text)" ] }, { "cell_type": "markdown", "id": "e4b23e4c-ba67-4fe7-a95c-172ad71ab8b4", "metadata": {}, "source": [ "#### 5.3 字符串查找和替换" ] }, { "cell_type": "code", "execution_count": 17, "id": "94435998-7580-49fe-b812-b65a75258a54", "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Position of 'great': 10\n", "Python is excellent for text processing\n" ] } ], "source": [ "text = \"Python is great for text processing\"\n", "\n", "# 查找子字符串\n", "position = text.find(\"great\")\n", "print(f\"Position of 'great': {position}\")\n", "\n", "# 替换子字符串\n", "new_text = text.replace(\"great\", \"excellent\")\n", "print(new_text)" ] }, { "cell_type": "markdown", "id": "75cc2929-68e4-484c-8489-e8079277014e", "metadata": {}, "source": [ "#### 5.4 改变字符串大小写" ] }, { "cell_type": "code", "execution_count": 18, "id": "021c7729-bf6d-4e60-a28c-fdf67b38ba1d", "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "python is great\n", "PYTHON IS GREAT\n", "Python Is Great\n" ] } ], "source": [ "text = \"Python is Great\"\n", "\n", "# 全部转换为小写\n", "lower_text = text.lower()\n", "print(lower_text)\n", "\n", "# 全部转换为大写\n", "upper_text = text.upper()\n", "print(upper_text)\n", "\n", "# 首字母大写\n", "title_text = text.title()\n", "print(title_text)" ] }, { "cell_type": "markdown", "id": "0707ad7d-a6b4-496e-8f1f-d28d6b811bc3", "metadata": {}, "source": [ "#### 5.5 去除空白字符" ] }, { "cell_type": "code", "execution_count": 20, "id": "8ca8471c-46de-4495-ab53-9e9075764d0f", "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "|Python is great|\n", "|Python is great |\n", "| Python is great|\n" ] } ], "source": [ "text = \" Python is great \"\n", "\n", "# 去除两端空白字符\n", "trimmed_text = text.strip()\n", "print(f\"|{trimmed_text}|\")\n", "\n", "# 去除左侧空白字符\n", "left_trimmed_text = text.lstrip()\n", "print(f\"|{left_trimmed_text}|\")\n", "\n", "# 去除右侧空白字符\n", "right_trimmed_text = text.rstrip()\n", "print(f\"|{right_trimmed_text}|\")" ] }, { "cell_type": "markdown", "id": "a749e823-4ab8-43d2-8da7-fc9b34f98ff1", "metadata": {}, "source": [ "### 6. 循环控制\n", "\n", "在编程中，循环是一种非常重要的结构，它允许我们重复执行一段代码。Python 中有两种主要的循环结构：`for` 循环和 `while` 循环。接下来，我们将介绍如何使用这些循环，并结合 `range`、`list` 和 `dict` 进行讲解。\n", "\n", "#### 6.1 For 循环遍历列表\n", "\n", "列表（`list`）是 Python 中的一种数据结构，可以存储多个值。我们可以使用 `for` 循环来遍历列表中的每个元素。" ] }, { "cell_type": "code", "execution_count": 41, "id": "6645da47-7378-4446-af5b-c8eeeb8d6680", "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "apple\n", "banana\n", "cherry\n" ] } ], "source": [ "# 定义一个列表\n", "fruits = ['apple', 'banana', 'cherry']\n", "\n", "# 遍历列表\n", "for fruit in fruits:\n", " print(fruit)" ] }, { "cell_type": "markdown", "id": "571bdd40-a16f-41c0-886b-227ae63752c7", "metadata": {}, "source": [ "#### 6.3 For 循环遍历字典\n", "\n", "字典（`dict`）是一种键值对的数据结构。我们可以使用 `for` 循环来遍历字典的键和值。" ] }, { "cell_type": "code", "execution_count": 42, "id": "7d837497-6fb9-4d9c-a7ae-d7a2f06aae8d", "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "name Alice\n", "age 25\n", "city New York\n" ] } ], "source": [ "# 定义一个字典\n", "person = {'name': 'Alice', 'age': 25, 'city': 'New York'}\n", "\n", "# 遍历字典的键\n", "for key in person:\n", " print(key, person[key])" ] }, { "cell_type": "markdown", "id": "2a2f9289-ed6f-466b-b2e9-1b6deb64d7e6", "metadata": {}, "source": [ "#### 6.4 While 循环\n", "\n", "`while` 循环在给定条件为 `True` 时重复执行一段代码。它适用于需要在循环中改变条件的情况。" ] }, { "cell_type": "code", "execution_count": 44, "id": "9d494e70-d499-4fa7-9454-af5677b7d275", "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "0\n", "1\n", "2\n", "3\n", "4\n" ] } ], "source": [ "# 使用 while 循环打印 0 到 4\n", "count = 0\n", "while count < 5:\n", " print(count)\n", " count += 1" ] } ], "metadata": { "kernelspec": { "display_name": "Python 3 (ipykernel)", "language": "python", "name": "python3" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 3 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython3", "version": "3.11.9" } }, "nbformat": 4, "nbformat_minor": 5 }