{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Dictionaries"
]
},
{
"cell_type": "code",
"execution_count": 1,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"{'name': 'Morty', 'age': 26}\n"
]
}
],
"source": [
"#declaring a dictionary variable\n",
"empty={} #empty dictionary\n",
"person={\"name\":\"John Smith\"} #dictionary with one key:value pair\n",
"customer={\n",
" \"name\":\"Morty\",\n",
" \"age\":26\n",
"} #dictionary with two key:value pair\n",
"print(customer)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Accessing dictionary information"
]
},
{
"cell_type": "code",
"execution_count": 2,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"John\n"
]
}
],
"source": [
"#accessing dictionary information through keys\n",
"person={\"name\":\"John\"}\n",
"print(person[\"name\"])"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Using the get method"
]
},
{
"cell_type": "code",
"execution_count": 3,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"John\n",
"None\n",
"Age is not available\n"
]
}
],
"source": [
"#using the get method to access dictionary information\n",
"person={\"name\":\"John\"}\n",
"print(person.get(\"name\")) #retrieve value of name key\n",
"print(person.get(\"age\")) #key does not exist,return None\n",
"print(person.get(\"age\",\"Age is not available\")) #get is a secure way to retrieve information"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Dictionaries with Lists"
]
},
{
"cell_type": "code",
"execution_count": 4,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"football\n"
]
}
],
"source": [
"#storing a list within a dictionary and accessing it\n",
"data={\"sports\":[\"baseball\",\"football\",\"hockey\",\"soccer\"]}\n",
"print(data[\"sports\"][1]) #first access the key , then index"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [],
"source": [
"#improperly storing a list within a dictionary\n",
"sports=[\"baseball\",\"football\",\"hockey\",\"soccer\"]\n",
"# sports_dict=dict(sports) #error, no key\n",
"sports_dict=dict({\"sports\":sports})"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Lists with Dictionaries"
]
},
{
"cell_type": "code",
"execution_count": 5,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"{'name': 'Kirsten'}\n",
"Kirsten\n"
]
}
],
"source": [
"#storing a dictionary within a list and accessing it\n",
"data = [\"John\",\"Dennies\",{\"name\":\"Kirsten\"}]\n",
"print(data[2]) #dictionary is at index 2\n",
"print(data[2][\"name\"]) #first access index, then key"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Dictionaries with Dictionaries"
]
},
{
"cell_type": "code",
"execution_count": 6,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"{'2018': 108, '2017': 93}\n",
"93\n"
]
}
],
"source": [
"#storing a dictionary within a dictionary and accessing it\n",
"data ={\n",
" \"team\":\"Boston Red Sox\",\n",
" \"wins\":{\"2018\":108,\"2017\":93}\n",
"}\n",
"print(data[\"wins\"])\n",
"print(data[\"wins\"][\"2017\"]) #first access the wins key, then next key"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [],
"source": [
"#Exercises\n",
"n,a=input(\"Enter name\"),input(\"Enter age\")\n",
"person={\"name\":n,\"age\":a}\n",
"print(person)"
]
},
{
"cell_type": "code",
"execution_count": 7,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"cheese\n",
"sausage\n",
"peppers\n"
]
}
],
"source": [
"pizza={\n",
" \"ingredients\":[\"cheese\",\"sausage\",\"peppers\"]\n",
"}\n",
"for ing in pizza[\"ingredients\"]:\n",
" print(ing)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Working with Dictionaries"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Adding new information"
]
},
{
"cell_type": "code",
"execution_count": 8,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"{'year': 2018, 'color': 'red'}\n",
"Year: 2018 \tColor: red\n"
]
}
],
"source": [
"#adding new key/value pairs to a dictionary\n",
"car={\"year\":2018}\n",
"car[\"color\"]=\"red\"\n",
"print(car)\n",
"print(\"Year: {} \\tColor: {}\".format(car[\"year\"],car[\"color\"]))"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Changing information"
]
},
{
"cell_type": "code",
"execution_count": 9,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Year: 2018 \tColor: blue\n"
]
}
],
"source": [
"#updating the value of key/value pair that already exists\n",
"car={\"year\":2018,\"color\":\"red\"}\n",
"car[\"color\"]=\"blue\"\n",
"print(\"Year: {} \\tColor: {}\".format(car[\"year\"],car[\"color\"]))"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Deleting information"
]
},
{
"cell_type": "code",
"execution_count": 10,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"{}\n"
]
}
],
"source": [
"#deleting a key/value pair from a dictionary\n",
"car={\"year\":2018}\n",
"try:\n",
" del car[\"year\"]\n",
" print(car)\n",
"except:\n",
" print(\"The car does not exits\")"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Looping a dictionary"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Looping only keys"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [],
"source": [
"#looping over a dictionary via keys\n",
"person={\"name\":\"John\",\"keys\":26}\n",
"for k in person.keys():\n",
" print(k)\n",
" print(person[k])\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Looping only values"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [],
"source": [
"#looping over a dictionary via values\n",
"person={\"name\":\"John\",\"age\":26}\n",
"for v in person.values():\n",
" print(v)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Looping Key-Value pairs"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [],
"source": [
"#looping over a dictionary via key/value pair\n",
"person={\"name\":\"John\",\"age\":26}\n",
"for k,v in person.items():\n",
" print(\"{} : {}\".format(k,v))"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Tuples, Sets, Frozensets"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Declaring a Tuple"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [],
"source": [
"#declaring a tuple\n",
"t1=(\"hello\",2,\"hello\") #with paren\n",
"t2=True,1 #without paren\n",
"print(t1)\n",
"print(t2)\n",
"print(type(t1),type(t2)) #both are tuples\n",
"#t1[0]=1 #tuples are immutable"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Declaring a Set"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [],
"source": [
"#declaring a set\n",
"s1=set([1,2,3,1]) #uses the set keyword,square brackets\n",
"s2={4,4,5} #uses curly brackets like dictionary\n",
"print(s1)\n",
"print(s2)\n",
"print(type(s1),type(s2))\n",
"s1.add(5) #use add method to add new items to a set\n",
"print(s1)\n",
"s1.remove(1) #use remove method to get rid of a value\n",
"print(s1)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Declaring a Frozenset"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [],
"source": [
"#declaring a frozenset\n",
"f=frozenset([1,2,3,4,2,1])\n",
"print(f)\n",
"print(type(f))"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [],
"source": [
"#Exercise\n",
"nums=[3,4,3,7,10]\n",
"s=set(nums)\n",
"print(s)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Reading & Writing files"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [],
"source": [
"#opening/creating and writing to a text file\n",
"f=open(\"test.txt\",\"w+\") #opening a file in writing and reading mode\n",
"f.write(\"This is a test\")\n",
"f.close() #anytime you open a file,you must close it\n",
"f=open(\"test.txt\",\"r\") #reading a file\n",
"data=f.read()\n",
"f.close()\n",
"print(data)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Writing to csv files"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [],
"source": [
"#opening/creating and writing to a csv file\n",
"import csv\n",
"with open(\"test.csv\",mode=\"w\",newline=\"\") as f:\n",
" w=csv.writer(f,delimiter=\",\")\n",
" w.writerow([\"Name\",\"City\"])\n",
" w.writerow([\"Craig Lou\",\"Taiwan\"])"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Reading from csv files"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [],
"source": [
"#reading from csv files\n",
"import csv\n",
"with open(\"test.csv\",mode=\"r\") as f:\n",
" r=csv.reader(f,delimiter=\",\")\n",
" for row in r:\n",
" print(row)"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [],
"source": [
"#Exercise\n",
"i=input(\"Enter your favourite no:\")\n",
"f=open(\"fav.txt\",\"w+\")\n",
"f.write(i)\n",
"f.close()"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [],
"source": [
"data={\n",
" \"name\":[\"Dave\",\"Jennis\",\"Peter\",\"Jess\"],\n",
" \"language\":[\"Python\",\"C\",\"Python\",\"Java\"]\n",
"}\n",
"import csv\n",
"with open(\"lang.csv\",mode=\"w\",newline=\"\") as f:\n",
" w=csv.writer(f,delimiter=\",\")\n",
" w.writerow([\"name\",\"language\"])\n",
" w.writerow([data[\"name\"][0],data[\"language\"][0]])\n",
" w.writerow([data[\"name\"][1],data[\"language\"][1]])\n",
" w.writerow([data[\"name\"][2],data[\"language\"][2]])\n",
" w.writerow([data[\"name\"][3],data[\"language\"][3]])\n",
" "
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Project - Creating a User Database with csv files"
]
},
{
"cell_type": "code",
"execution_count": 11,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Thanks for using our software\n"
]
}
],
"source": [
"import csv\n",
"from IPython.display import clear_output\n",
"#handle user registration and writing to a csv file\n",
"def registerUser():\n",
" with open(\"users.csv\",mode=\"a\",newline=\"\") as f:\n",
" w=csv.writer(f,delimiter=\",\")\n",
" print(\"To Register, enter your info\")\n",
" email=input(\"E-mail: \")\n",
" password=input(\"Password: \")\n",
" password2=input(\"Retype password: \")\n",
" clear_output()\n",
" if password == password2:\n",
" w.writerow([email,password])\n",
" print(\"You are now registered\")\n",
" else:\n",
" print(\"Something went wrong.Pl try again\")\n",
"#ask for user info , return true for correct login and false for incorrect login\n",
"def loginUser():\n",
" print(\"To Login, enter your info\")\n",
" email=input(\"E-mail: \")\n",
" password=input(\"Password: \")\n",
" clear_output()\n",
" with open(\"users.csv\",mode=\"r\") as f:\n",
" r=csv.reader(f,delimiter=\",\")\n",
" for row in r:\n",
" if row == [email,password]:\n",
" print(\"You are logged in!\")\n",
" return True\n",
" print(\"Something went wrong.Pl try again\")\n",
" return False\n",
"#variables for main loop\n",
"active = True\n",
"logged_in = False\n",
"#main loop\n",
"while active:\n",
" if logged_in:\n",
" print(\"1. Logout\\n2. Quit\")\n",
" else:\n",
" print(\"1. Login\\n2. Register\\n3. Quit\")\n",
" choice=input(\"What would you like to do: \").lower()\n",
" clear_output()\n",
" if choice == \"register\" and logged_in == False:\n",
" registerUser()\n",
" elif choice == \"login\" and logged_in == False:\n",
" logged_in = loginUser()\n",
" elif choice == \"quit\":\n",
" active = False\n",
" print(\"Thanks for using our software\")\n",
" elif choice == \"logout\" and logged_in == True:\n",
" logged_in = False\n",
" print(\"Your are now logged out\")\n",
" else:\n",
" print(\"Sorry. Pl try again\")\n",
"\n",
"\n"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [],
"source": []
}
],
"metadata": {
"kernelspec": {
"display_name": "Python 3",
"language": "python",
"name": "python3"
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"language_info": {
"codemirror_mode": {
"name": "ipython",
"version": 3
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"file_extension": ".py",
"mimetype": "text/x-python",
"name": "python",
"nbconvert_exporter": "python",
"pygments_lexer": "ipython3",
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