generators.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Python 生成器"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 生成器函数"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [],
   "source": [
    "def squares_generator(limit):\n",
    "    for i in range(1, limit + 1):\n",
    "        yield i ** 2"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1\n",
      "4\n",
      "9\n",
      "16\n",
      "25\n"
     ]
    }
   ],
   "source": [
    "for square in squares_generator(5):\n",
    "    print(square)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1\n",
      "4\n",
      "9\n"
     ]
    },
    {
     "ename": "StopIteration",
     "evalue": "",
     "output_type": "error",
     "traceback": [
      "\u001b[1;31m---------------------------------------------------------------------------\u001b[0m",
      "\u001b[1;31mStopIteration\u001b[0m                             Traceback (most recent call last)",
      "Cell \u001b[1;32mIn[14], line 5\u001b[0m\n\u001b[0;32m      3\u001b[0m \u001b[39mprint\u001b[39m(\u001b[39mnext\u001b[39m(gen))  \u001b[39m# Output: 4\u001b[39;00m\n\u001b[0;32m      4\u001b[0m \u001b[39mprint\u001b[39m(\u001b[39mnext\u001b[39m(gen))  \u001b[39m# Output: 9\u001b[39;00m\n\u001b[1;32m----> 5\u001b[0m \u001b[39mprint\u001b[39m(\u001b[39mnext\u001b[39;49m(gen))  \u001b[39m# Raises StopIteration since the generator has no more elements\u001b[39;00m\n",
      "\u001b[1;31mStopIteration\u001b[0m: "
     ]
    }
   ],
   "source": [
    "gen = squares_generator(3)\n",
    "print(next(gen))  # Output: 1\n",
    "print(next(gen))  # Output: 4\n",
    "print(next(gen))  # Output: 9\n",
    "print(next(gen))  # Raises StopIteration since the generator has no more elements"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 16,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[1, 4, 9, 16]\n",
      "(1, 4, 9, 16)\n"
     ]
    }
   ],
   "source": [
    "gen = squares_generator(4)\n",
    "square_list = list(gen)\n",
    "print(square_list)  # Output: [1, 4, 9, 16]\n",
    "\n",
    "square_tuple = tuple(squares_generator(4))\n",
    "print(square_tuple)  # Output: (1, 4, 9, 16)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 无限序列"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [],
   "source": [
    "def fibonacci_generator():\n",
    "    a, b = 0, 1\n",
    "    while True:\n",
    "        yield a\n",
    "        a, b = b, a + b"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 18,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "0\n",
      "1\n",
      "1\n",
      "2\n",
      "3\n",
      "5\n",
      "8\n",
      "13\n",
      "21\n",
      "34\n"
     ]
    }
   ],
   "source": [
    "fib_gen = fibonacci_generator()\n",
    "\n",
    "# Print the first 10 Fibonacci numbers\n",
    "for _ in range(10):\n",
    "    print(next(fib_gen))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 22,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "102334155\n",
      "165580141\n",
      "267914296\n",
      "433494437\n",
      "701408733\n",
      "1134903170\n",
      "1836311903\n",
      "2971215073\n",
      "4807526976\n",
      "7778742049\n"
     ]
    }
   ],
   "source": [
    "for _ in range(10):\n",
    "    print(next(fib_gen))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 推导式得到生成器"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 23,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "<class 'generator'>\n",
      "1\n",
      "4\n",
      "9\n",
      "16\n",
      "25\n"
     ]
    }
   ],
   "source": [
    "squares_generator = (x ** 2 for x in range(1, 6))\n",
    "\n",
    "print(type(squares_generator))\n",
    "# Iterate over the generator and print the squares\n",
    "for square in squares_generator:\n",
    "    print(square)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 24,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2\n",
      "4\n",
      "6\n",
      "8\n",
      "10\n"
     ]
    }
   ],
   "source": [
    "even_numbers_generator = (x for x in range(1, 11) if x % 2 == 0)\n",
    "\n",
    "# Iterate over the generator and print the even numbers\n",
    "for even_number in even_numbers_generator:\n",
    "    print(even_number)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "沉浸式翻译"
   ]
  }
 ],
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