Chapter -11 (Dictionary)

For learn how to download and install python link here: How to download and install python in window

For learn how to run and execute the code in python link here:How to write and run the code

In this blog, the format is first I write Code then Result of that code. You can directly copy the code and so your time save in written that code. Also , image of the code and result and after which it contain explanation of the code.

Example-1: Some important expression

Example-2: Simple dictionary

Code:

d = {'A':100, 'B':200}

print(d['A'])

Result:

100

Explanation:- Here in 1st line first we create dictionary. Dictionary create in curly bracket and specify the value of name. In this we use A and B.

For example, you go to shop here they return product name and in front of it, its value. The work of dictionary is same.

<Here A and B show the key and 100 and 200 show value.>

Example-3: If use enter dog , cat, mouse then give its definition.
d = {'dog' : 'has a tail and goes woof!',
'cat' : 'says meow',
'mouse' : 'chased by cats'}

Code:

d = {'dog' : 'has a tail and goes woof!',

'cat' : 'says meow',

'mouse' : 'chased by cats'}

word=input('Enter name:')

print('The defination of:', d[word])

Result:

Enter name: cat

The defination is: says meow

Explanation:- It is similar to previous example.

Example-4: To create a dictionary of roman number.

Code:

number= {'I':1, 'V':5, 'X':10, 'L':50 , 'C':100}

print (number['V'])

Result:

5

Explanation:- Similar to example-1

Example-5: Here some name given with their value:
points = {'A':1, 'B':3, 'C':3, 'D':2, 'E':1, 'F':4, 'G':2,'H':4, 'I':1, 'J':8, 'K':5, 'L':1, 'M':3, 'N':1,'O':1, 'P':3, 'Q':10, 'R':1, 'S':1, 'T':1, 'U':1,'V':4, 'W':4, 'X':8, 'Y':4, 'Z':10}

Write a program and user enter 5 times its choice and then add all the score.

Code:

points = {'A':1, 'B':3, 'C':3, 'D':2, 'E':1, 'F':4, 'G':2,

'H':4, 'I':1, 'J':8, 'K':5, 'L':1, 'M':3, 'N':1,

'O':1, 'P':3, 'Q':10, 'R':1, 'S':1, 'T':1, 'U':1,

'V':4, 'W':4, 'X':8, 'Y':4, 'Z':10}

count=0

for i in range(6):

    word=input('Enter your choice:')

    count=count+points[word]

    print('The total score is:',count)

Result:

Enter your choice:Y

The total score is: 4

Enter your choice:F

The total score is: 8

Enter your choice:R

The total score is: 9

Enter your choice:F

The total score is: 13

Enter your choice:C

The total score is: 16

Enter your choice:D

The total score is: 18

Explanation:- First we create dictionary and then by the help of for loop and count we add all the input answer and simply get the result.

Example-6: Represent a deck of card.

Code:

deck = [{'value':i, 'suit':c}

    for c in ['spades', 'clubs', 'hearts', 'diamonds']

    for i in range(1,14)]

print(deck)

Result:

[{'value': 1, 'suit': 'spades'}, {'value': 2, 'suit': 'spades'}, {'value': 3, 'suit': 'spades'}, {'value': 4, 'suit': 'spades'}, {'value': 5, 'suit': 'spades'}, {'value': 6, 'suit': 'spades'}, {'value': 7, 'suit': 'spades'}, {'value': 8, 'suit': 'spades'}, {'value': 9, 'suit': 'spades'}, {'value': 10, 'suit': 'spades'}, {'value': 11, 'suit': 'spades'}, {'value': 12, 'suit': 'spades'}, {'value': 13, 'suit': 'spades'}, {'value': 1, 'suit': 'clubs'}, {'value': 2, 'suit': 'clubs'}, {'value': 3, 'suit': 'clubs'}, {'value': 4, 'suit': 'clubs'}, {'value': 5, 'suit': 'clubs'}, {'value': 6, 'suit': 'clubs'}, {'value': 7, 'suit': 'clubs'}, {'value': 8, 'suit': 'clubs'}, {'value': 9, 'suit': 'clubs'}, {'value': 10, 'suit': 'clubs'}, {'value': 11, 'suit': 'clubs'}, {'value': 12, 'suit': 'clubs'}, {'value': 13, 'suit': 'clubs'}, {'value': 1, 'suit': 'hearts'}, {'value': 2, 'suit': 'hearts'}, {'value': 3, 'suit': 'hearts'}, {'value': 4, 'suit': 'hearts'}, {'value': 5, 'suit': 'hearts'}, {'value': 6, 'suit': 'hearts'}, {'value': 7, 'suit': 'hearts'}, {'value': 8, 'suit': 'hearts'}, {'value': 9, 'suit': 'hearts'}, {'value': 10, 'suit': 'hearts'}, {'value': 11, 'suit': 'hearts'}, {'value': 12, 'suit': 'hearts'}, {'value': 13, 'suit': 'hearts'}, {'value': 1, 'suit': 'diamonds'}, {'value': 2, 'suit': 'diamonds'}, {'value': 3, 'suit': 'diamonds'}, {'value': 4, 'suit': 'diamonds'}, {'value': 5, 'suit': 'diamonds'}, {'value': 6, 'suit': 'diamonds'}, {'value': 7, 'suit': 'diamonds'}, {'value': 8, 'suit': 'diamonds'}, {'value': 9, 'suit': 'diamonds'}, {'value': 10, 'suit': 'diamonds'}, {'value': 11, 'suit': 'diamonds'}, {'value': 12, 'suit': 'diamonds'}, {'value': 13, 'suit': 'diamonds'}]

Explanation:- Here first we use value and card suit then give the range so that it form the complete deck.

Example-7: Copy this dictionary d = {'A':100, 'B':200}

Code:

d = {'A':100, 'B':200}

d2 = d.copy()

print(d2)

Result:

{'A': 100, 'B': 200}

Explanation:- Simply by use of copy command you can copy the dictionary.

Example-8: Write the value of the key and if key not present in dictionary then show not found. Take d = {'A':100, 'B':200}

Code:

d = {'A':100, 'B':200}

letter = input('Enter a letter: ')

if letter in d:

    print('The value is', d[letter])

else:

    print('Not in dictionary')

Result:

Enter a letter: A

The value is 100

< When you restart the shell>

Enter a letter: J

Not in dictionary

Explanation:- Simply you understand if read previous chapter.

Example-9.1: Write a program and find the key in dictionary.

Code:

d = {'A':100, 'B':200, 'C':100}

L = [x[0] for x in d.items() if x[1]==100]

print(L)

Result:

['A', 'C']

Explanation:- You easily able to understand all thing except why put x[0]. For this see in next example.

Example-9.2: Write a program and find the key in dictionary.

Code:

d = {'A':100, 'B':200, 'C':100}

L = [x[1] for x in d.items() if x[1]==100]

print(L)

Result:

[100,100]

Explanation:- In the previous example you see A , C but here 100 and 100, because '0' denote for key and '1' denote for value.

Example-10: To convert list into dictionary.

Code:

d = dict([('A',100),('B',300)])

print(d)

Result:

{'A': 100, 'B': 300}

Explanation:- By using dict command we able to convert list into dictionary.

Example-11: How to open the text file from the pc. First save the file to your desktop, In my case, I save a file with the name of text in desktop.

Code:

t=open('text.txt').read()

print(t)

Result:

ajshfhgotgho ho osaj opijsdjrop ujiopaj iopejtaioa opajys jaopihjy ojc lhl ghncxog hohj goi hjro rioehjr iozjsol; ejo;jfo;d hjol;j 

Explanation:- In the result you see random word these same written in that file , which I save in the desktop of my Pc. You can check own.

Example-12: Open the random file from your pc and then remove all the punctuation from the file. I take the file which is previous save on my desktop as the name of 'text'.

Code:

t=open('text.txt').read()

from string import punctuation

text=t.lower()

for p in punctuation:

    text=text.replace(p,'')

words=text.split()

print(words)

Result:

['ajshfhgotgho', 'ho', 'osaj', 'opijsdjrop', 'ujiopaj', 'iopejtaioa', 'opajys', 'jaopihjy', 'ojc', 'lhl', 'ghncxog', 'hohj', 'goi', 'hjro', 'rioehjr', 'iozjsol', 'ejojfod', 'hjolj']

Explanation:- You see these code 'for p in punctuation' in previous chapter, in the next line you see replace so this command help in replace the punctuation from the file.

<If you want to join then use ''.join(words)

Example-13: Give the value to the key in the text file you save on your desktop.

Code:

t=open('text.txt').read()

from string import punctuation

text=t.lower()

for p in punctuation:

    text=text.replace(p,'')

words=text.split()

d = {}

for w in words:

    if w in d:

        d[w] = d[w] + 1

    else:

        d[w] = 1

print(d)

Result:

{'ajshfhgotgho': 1, 'ho': 1, 'osaj': 1, 'opijsdjrop': 1, 'ujiopaj': 1, 'iopejtaioa': 1, 'opajys': 1, 'jaopihjy': 1, 'ojc': 1, 'lhl': 1, 'ghncxog': 1, 'hohj': 1, 'goi': 1, 'hjro': 1, 'rioehjr': 1, 'iozjsol': 1, 'ejojfod': 1, 'hjolj': 1}

Explanation:- Here you see command like previous example but few more code which is used to give the value to the key. Here all value are 1 beacuse use else: d[w]=1 ,and if you put here 2 then all value are 2.

Example-14: Arrange all the key in alphabetical order take the file that you save on you desktop as the name of text.

Code:

t=open('text.txt').read()

from string import punctuation

text=t.lower()

for p in punctuation:

    text=text.replace(p,'')

words=text.split()

d = {}

for w in words:

    if w in d:

        d[w] = d[w] + 1

    else:

        d[w] = 1

items = list(d.items())

items.sort()

for i in items:

    print(i)

Result:

('ajshfhgotgho', 1)

('ejojfod', 1)

('ghncxog', 1)

('goi', 1)

('hjolj', 1)

('hjro', 1)

('ho', 1)

('hohj', 1)

('iopejtaioa', 1)

('iozjsol', 1)

('jaopihjy', 1)

('lhl', 1)

('ojc', 1)

('opajys', 1)

('opijsdjrop', 1)

('osaj', 1)

('rioehjr', 1)

('ujiopaj', 1)

Explanation:- Here we first convert into list by using d.items(). Then use sort command which arrange all the key in the alphabetical order. You read sort command in chapter-7 (list).

Example-15: Write a program and print first the value of the dictionary then the key arrange in alphabetical order. Take example the same file which you save on your desktop.

Code:

t=open('text.txt').read()

from string import punctuation

text=t.lower()

for p in punctuation:

    text=text.replace(p,'')

words=text.split()

d = {}

for w in words:

    if w in d:

        d[w] = d[w] + 1

    else:

        d[w] = 1

items = list(d.items())

items = [(i[1], i[0]) for i in items]

items.sort()

for i in items:

    print(i)

Result:

(1, 'ajshfhgotgho')

(1, 'ejojfod')

(1, 'ghncxog')

(1, 'goi')

(1, 'hjolj')

(1, 'hjro')

(1, 'ho')

(1, 'hohj')

(1, 'iopejtaioa')

(1, 'iozjsol')

(1, 'jaopihjy')

(1, 'lhl')

(1, 'ojc')

(1, 'opajys')

(1, 'opijsdjrop')

(1, 'osaj')

(1, 'rioehjr')

(1, 'ujiopaj')

Explanation:- Here we use items = [(i[1], i[0]) for i in items] which first write the value and then key. It is same to previous example.

Practice Question: