7 Tricks to Write Better Python Code.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# 7 Tricks to Write Better Python Code"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 1 - Use \"enumerate\"."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "cities = [\"barcelona\", \"madrid\", \"istanbul\", \"paris\"]"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### - Bad Way"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "0 barcelona\n",
      "1 madrid\n",
      "2 istanbul\n",
      "3 paris\n"
     ]
    }
   ],
   "source": [
    "i = 0\n",
    "\n",
    "for city in cities:\n",
    "    print(i, city)\n",
    "    i+=1"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### + Good Way"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "0 barcelona\n",
      "1 madrid\n",
      "2 istanbul\n",
      "3 paris\n"
     ]
    }
   ],
   "source": [
    "for i, city in enumerate(cities):\n",
    "    print(i, city)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 2 - Use \"zip\"."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [],
   "source": [
    "x_list = [1,2,3]\n",
    "y_list = [2,4,6]"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### - Bad Way"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1 2\n",
      "2 4\n",
      "3 6\n"
     ]
    }
   ],
   "source": [
    "for i in range(len(x_list)):\n",
    "    x = x_list[i]\n",
    "    y = y_list[i]\n",
    "    print(x, y)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### + Good Way"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1 2\n",
      "2 4\n",
      "3 6\n"
     ]
    }
   ],
   "source": [
    "for x,y in zip(x_list, y_list):\n",
    "    print(x, y)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 3 - Use \"swap\"."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [],
   "source": [
    "x = 10\n",
    "y = -10"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### - Bad Way"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Before : x = 10, y = -10\n"
     ]
    }
   ],
   "source": [
    "print(\"Before : x = %d, y = %d\" %(x,y))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [],
   "source": [
    "tmp = y\n",
    "y = x\n",
    "x = tmp"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "After : x = -10, y = 10\n"
     ]
    }
   ],
   "source": [
    "print(\"After : x = %d, y = %d\" %(x,y))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### + Good Way"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Before : x = -10, y = 10\n"
     ]
    }
   ],
   "source": [
    "print(\"Before : x = %d, y = %d\" %(x,y))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "metadata": {},
   "outputs": [],
   "source": [
    "x, y = y, x"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "After : x = 10, y = -10\n"
     ]
    }
   ],
   "source": [
    "print(\"After : x = %d, y = %d\" %(x,y))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 4 - Use \"get\"."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "metadata": {},
   "outputs": [],
   "source": [
    "ages = {\n",
    "    \"Mary\" : 31,\n",
    "    \"Jonathan\" : 28\n",
    "}"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### - Bad Way"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 16,
   "metadata": {},
   "outputs": [],
   "source": [
    "# age = ages[\"Dick\"] this code has error, because dictionary has'nt \"Dick\" key."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 17,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Dick is unknown years old.\n"
     ]
    }
   ],
   "source": [
    "if \"Dick\" in ages:\n",
    "    age = ages[\"Dick\"]\n",
    "else: \n",
    "    age = \"unknown\"\n",
    "    \n",
    "print(\"Dick is %s years old.\"%age)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### + Good Way"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 18,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Dick is unknown years old.\n"
     ]
    }
   ],
   "source": [
    "age = ages.get(\"Dick\", \"unknown\")\n",
    "print(\"Dick is %s years old.\"%age)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 5 - Use \"else\" after for loop."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 19,
   "metadata": {},
   "outputs": [],
   "source": [
    "needle = \"e\"\n",
    "haystack = [\"a\", \"b\", \"c\",\"d\"]"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### - Bad Way"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 20,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Not found!\n"
     ]
    }
   ],
   "source": [
    "found = False\n",
    "\n",
    "for letter in haystack:\n",
    "    if needle == letter:\n",
    "        print(\"Found!\")\n",
    "        found = True\n",
    "        break\n",
    "        \n",
    "if not found:\n",
    "        print(\"Not found!\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### + Good Way"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 21,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Not found!\n"
     ]
    }
   ],
   "source": [
    "for letter in haystack:\n",
    "    if needle == letter:\n",
    "        print(\"Found!\")\n",
    "        break\n",
    "else: # if no break occured.\n",
    "    print(\"Not found!\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 6 - Use \"with\"."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### - Bad Way"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 22,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "hello world.\n",
      "how areu?\n",
      "im good.\n"
     ]
    }
   ],
   "source": [
    "f = open(\"text.txt\")\n",
    "\n",
    "text = f.read()\n",
    "for line in text.split(\"\\n\"):\n",
    "    print(line)\n",
    "    \n",
    "f.close()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### + Good Way"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 23,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "hello world.\n",
      "\n",
      "how areu?\n",
      "\n",
      "im good.\n"
     ]
    }
   ],
   "source": [
    "f = open(\"text.txt\")\n",
    "\n",
    "for line in f:\n",
    "    print(line)\n",
    "\n",
    "f.close()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### + Best Way"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 24,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "hello world.\n",
      "\n",
      "how areu?\n",
      "\n",
      "im good.\n"
     ]
    }
   ],
   "source": [
    "with open(\"text.txt\") as f:\n",
    "    for line in f:\n",
    "        print(line)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 7 - Use \"try - catch\""
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 25,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Converting!\n",
      "1\n",
      "Done\n"
     ]
    }
   ],
   "source": [
    "print(\"Converting!\")\n",
    "print(int(\"1\"))\n",
    "print(\"Done\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### - Bad Way"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 26,
   "metadata": {
    "scrolled": true
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Converting!\n",
      "Conversion successful!\n",
      "Done\n"
     ]
    }
   ],
   "source": [
    "print(\"Converting!\")\n",
    "\n",
    "try:\n",
    "    int(\"1\")\n",
    "except:\n",
    "    print(\"Conversion failed!\")\n",
    "else:\n",
    "    print(\"Conversion successful!\")\n",
    "finally:\n",
    "    print(\"Done\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### + Good Way"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 27,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Converting!\n",
      "Conversion failed!\n",
      "Done\n"
     ]
    }
   ],
   "source": [
    "print(\"Converting!\")\n",
    "\n",
    "try:\n",
    "    int(\"x\")\n",
    "except:\n",
    "    print(\"Conversion failed!\")\n",
    "else:\n",
    "    print(\"Conversion successful!\")\n",
    "finally:\n",
    "    print(\"Done\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "**Source : https://www.youtube.com/watch?v=pQmKDXUh2I8**"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "**Source created by  Sebastiaan Mathôt Youtube Channel.**"
   ]
  }
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