Matplotlib - plotting a dictionary using matplot lib

 # Dictionary - Histograms and matplotlib

# Create a histogram based on the frequency of characters in given string

# Histogram - String - Word Frequency

import matplotlib.pyplot as plt

import operator

string1 = "An algorithm is a step-by-step procedure to solve a given problem. It is a well-defined computational procedure that takes some values as input, manipulates them using a set of instructions and produces some values as output and terminates in a finite amount of time. An algorithm, when formally written in a programming language is called a program, or code. Derivation of an algorithm that solves the problem and conversion of the algorithm into code, together,  is known as Algorithmic Problem Solving."

string1 = string1.lower()

ch = set(string1)

D = {c:string1.count(c) for c in ch if c.isalpha()}  

print("Histogram")

print("Length of dictionary = ", len(D))

print(D)

plt.bar(range(len(D)), list(D.values()), align='center')

plt.xticks(range(len(D)), list(D.keys()))

plt.xlabel('Character')

plt.ylabel('Frequency')

plt.title('Character Frequency in given string.')

plt.show()

"""

Output

>python matplot.py

Histogram

Length of dictionary =  22

{'k': 2, 'e': 40, 'n': 30, 'g': 14, 's': 26, 'u': 14, 'o': 38, 'i': 32, 't': 37, 'r': 25, 'l': 22, 'b': 4, 'w': 4, 'f': 7, 'p': 14, 'v': 8, 'a': 39, 'y': 2, 'm': 20, 'd': 12, 'c': 10, 'h': 12}

"""

Dictionary - Histogram - character frequency of a string

 # Dictionary - Histograms

# Create a histogram based on the frequency of characters in given string

# Histogram - String - Word Frequency

import operator

string1 = "An algorithm is a step-by-step procedure to solve a given problem. It is a well-defined computational procedure that takes some values as input, manipulates them using a set of instructions and produces some values as output and terminates in a finite amount of time. An algorithm, when formally written in a programming language is called a program, or code. Derivation of an algorithm that solves the problem and conversion of the algorithm into code, together,  is known as Algorithmic Problem Solving."

string1 = string1.lower()

ch = set(string1)

D = {c:string1.count(c) for c in ch if c.isalpha()}  

print("Histogram")

print("Length of dictionary = ", len(D))

print(D)

DSorted = sorted(D.items(), key=operator.itemgetter(1), reverse=True)

D_max3 = dict(DSorted[:3])

print("Most frequently used 3 characters:")

print(D_max3)

"""

Sample output

>python Dict_Hist.py

Histogram

Length of dictionary =  22

{'t': 37, 'a': 39, 'w': 4, 'l': 22, 'g': 14, 'h': 12, 'o': 38, 'u': 14, 's': 26, 'i': 32, 'm': 20, 'e': 40, 'd': 12, 'c': 10, 'r': 25, 'v': 8, 'n': 30, 'b': 4, 'y': 2, 'p': 14, 'k': 2, 'f': 7}

Most frequently used 3 characters:

{'e': 40, 'a': 39, 'o': 38}

"""

Dictionary manipulation - sorting

 # Dictionary Manipulation

"""

Consider two lists

NAMES = ['Alice', 'Larry', 'Cathy', 'Gary', 'Dan', 'Bob','Ed', 'Helen', 'Jack', 'Irene', 'Frank', 'Kelly']

AGES = [20, 21, 18, 18, 19, 20, 20, 19, 19, 19, 22, 19]

These lists match up, so Alice’s age is 20, Larry’s age is 21, and so on. Write a program that 

1. Combines these lists into a dictionary.

2. Reads a name and returns the age.

3. Reads an age and returns the names of all the people who are that age.

4. Sort dictionary by name.

5. Sort dictionary by age.

"""

# Program

import operator

# Given List

NAMES = ['Alice', 'Larry', 'Cathy', 'Gary', 'Dan', 'Bob','Ed', 'Helen', 'Jack', 'Irene', 'Frank', 'Kelly']

AGES = [20, 21, 18, 18, 19, 20, 20, 19, 19, 19, 22, 19]

# 1. Combines these lists into a dictionary.

D = { k:v for k,v in zip(NAMES,AGES)}

print(D)

# 2. Reads a name and returns the age.

Name = input("Enter name : ")

if Name in D:

print("Name :",Name)

print("Age :",D[Name])

else:

print("No data for",Name)

# 3. Reads an age and returns the names of all the people who are that age.

Age = int(input("Enter age : "))

Keys = [k for k,v in D.items() if v==Age]

if (len(Keys)==0):

print("No match for given age")

else:

print("People in same age:")

for k in Keys:

print(k)

# 4. Sort dictionary by name.

SD_Keys = {k:D[k] for k in sorted(D)}

print(SD_Keys)

# 5. Sort dictionary by age.

# Sorts by value and for same values sorts keys lexicographically 

SD_val = {v[0] : v[1] for v in sorted(D.items(), key = lambda x: (x[1], x[0]))}

print(SD_val)

File handling 18: Files and dictionary, Histogram, character frequency

# Write a program that creates a dictionary
# of the frequency of all characters in a file.
# display five most frequently occuring characters

# Files, Dictionary and Command line arguments
# Histogram - Character frequency

import sys
import operator

fname = sys.argv[1]
fs = open(fname, "r")

Char_freq = {}

while(True):
    Line = fs.readline().strip().lower()
   
    if not Line:
        break
   
    for ch in Line:
        if (ch.isalpha()):
            if ch in Char_freq:
                Char_freq[ch] += 1
            else:
                Char_freq[ch] = 1
           
for ch in Char_freq:
    print(ch, Char_freq[ch])

List1 = sorted(Char_freq.items(), key=operator.itemgetter(1), reverse=True)

print("Five most frequently occuring characters :")
for k,v in List1[0:5]:
    print(k,v)

fs.close()

File Handling 17: Files and Dictionary: Histogram, Word Frequency, remove noise words

# Write a program that creates a dictionary
# of the frequency of all words in a file.

# Files, Dictionary and Command line arguments
# Histogram - Word frequency

import sys

fname = sys.argv[1]
fs = open(fname, "r")

Word_freq = {}

while(True):
new_Line = ""
Line = fs.readline().strip().lower()

if not Line:
break

for ch in Line:
if (ch.isalpha() or ch.isspace()):
new_Line+=ch
L = new_Line.split(" ")

for wd in L:
if wd in Word_freq:
Word_freq[wd] += 1
else:
Word_freq[wd] = 1

for ele in Word_freq:
print(ele.ljust(15), Word_freq[ele])

print("Number of unique words in file = ", len(Word_freq))

fs.close()




# Write a program that creates a dictionary
# of the frequency of all words in a file.
# Remove noise words in file like a, an, the etc

# Files, Dictionary and Command line arguments
# Histogram - Word frequency

import sys

fname = sys.argv[1]
fs = open(fname, "r")

Word_freq = {}

Noise_words = ['an', 'as', 'of', 'it','by',  'to', 'so', 'do', 'be', 'up', 'on', 'ie', 'its', 'are', 'all', 'has', 'can', 'how', 'end', 'any', 'may', 'for', 'will', 'use', 'one', 'two', 'the', 'also', 'have', 'this', 'that', 'what', 'where', 'when', 'then', 'those', 'from', 'once', 'more', 'most' ]

while(True):
new_Line = ""
Line = fs.readline().strip().lower()

if not Line:
break

for ch in Line:
if (ch.isalpha() or ch.isspace()):
new_Line+=ch
L = new_Line.split(" ")

for wd in L:
if (len(wd)<=1 or wd in Noise_words):
continue

if wd in Word_freq:
Word_freq[wd] += 1
else:
Word_freq[wd] = 1

for ele in Word_freq:
print(ele.ljust(15), Word_freq[ele])

print("Number of unique words in file = ", len(Word_freq))

fs.close()

Histogram - String - Word frequency

# Histogram - String - Word Frequency

import operator

string1 = "An algorithm is a step-by-step procedure to solve a given problem. It is a well-defined computational procedure that takes some values as input, manipulates them using a set of instructions and produces some values as output and terminates in a finite amount of time. An algorithm, when formally written in a programming language is called a program, or code. Derivation of an algorithm that solves the problem and conversion of the algorithm into code, together,  is known as Algorithmic Problem Solving."
string1 = string1.lower()

string1 = string1.replace(".", "")
string1 = string1.replace(",", "")
string1 = string1.replace("-", " ")

List1 = string1.split(" ")

dict1 = {}
for ele in List1:
    if ele in dict1:
        dict1[ele] += 1
    else:
        dict1[ele] = 1
print("Histogram")
print("Length of dictionary = ", len(dict1))
print(dict1)

List2 = sorted(dict1.items(), key=operator.itemgetter(1), reverse=True)

dict2 = dict(List2[:3])
print("Most frequently used 3 words:")
print(dict2)

Histogram - String - Character frequency

# Histogram - Character frequency

import operator

string1 = "An algorithm is a step-by-step procedure to solve a given problem. It is a well-defined computational procedure that takes some values as input, manipulates them using a set of instructions and produces some values as output and terminates in a finite amount of time. An algorithm, when formally written in a programming language is called a program, or code. Derivation of an algorithm that solves the problem and conversion of the algorithm into code, together,  is known as Algorithmic Problem Solving."
string1 = string1.lower()

dict1 = {}
for idx in range(97, 123, 1):
    count = string1.count(chr(idx))
    if(count != 0):
        dict1[chr(idx)] = count

print("Histogram")
print(dict1)


List1 = sorted(dict1.items(), key=operator.itemgetter(1), reverse=True)
dict2 = dict(List1[:5])
print("Most frequent 5 characters")
print(dict2)