Chapter6.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

# looping through the string.
# Example # 1
# myString = input("Please enter a string: ")
# index = 0
# while index < len(myString):
#     letter = myString[index]
#     print(index, ":",letter)
#     index = index+1
#-----------------------------------------------------------------------------------------------------------------------
# __author__ = 'asim'
# Exercise 6.1 Write a while loop that starts at the last character in the string and
# works its way backwards to the first character in the string, printing each letter on
# a separate line, except backwards.
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Exercise 6.1 Write a while loop that starts at the last character in the string and works its way backwards to the
# first character in the string, printing each letter on a separate line, except backwards

# myString = input("Please enter a string: ")
# index = len(myString)
# while index > 0:
#     letter = myString[index-1]
#     print(index,":", letter)
#     index = index-1

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# String Slices:
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# MySubString1 = "Please enter a string: "
# MySubString1 = myString1[0:8]
# MySubString1
# print MySubString1
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#Exercise 6.2 Given that fruit is a string, what does fruit[:] mean?
# fruit = 'orange'
# print fruit[:]
#-----------------------------------------------------------------------------------------------------------------------
# Exercise 6.3 Encapsulate this code in a function named count, and generalize it
# so that it accepts the string and the letter as arguments.
# def count(word):
#     x = 0
#     for letter in word:
#         if letter == 'a':
#             x = x + 1
#     return x

# myString = raw_input("Please enter a fruit name and it will give you back count of letter 'a' in it: ")
# print count(myString)

#-----------------------------------------------------------------------------------------------------------------------
# fruit = "Orange"
# print 'a' in fruit
#-----------------------------------------------------------------------------------------------------------------------
# Exercise 6.4 There is a string method called count that is similar to the function
# in the previous exercise. Read the documentation of this method at docs.python.
# org/library/string.html and write an invocation that counts the number of
# times the letter a occurs in 'banana'.
#-----------------------------------------------------------------------------------------------------------------------
# fruit = raw_input("Please enter some fruit name: ")
# print "No of A's in your given string are: ",fruit.lower().count('a')

#-----------------------------------------------------------------------------------------------------------------------
# Exercise 6.5 Take the following Python code that stores a string:‘
# str = 'X-DSPAM-Confidence: 0.8475'
# Use find and string slicing to extract the portion of the string after the colon character and then use the float
# function to convert the extracted string into a floating point number.
#-----------------------------------------------------------------------------------------------------------------------
# str = "X-DSPAM-Confidence: 0.8475"
# pos = str.find(":")
# getNumber = float(str[pos+1:])
# print getNumber

#-----------------------------------------------------------------------------------------------------------------------
# Exercise 6.6 Read the documentation of the string methods at docs.python.org/lib/string-methods.html. You might want
# to experiment with some of them to make sure you understand how they work. strip and replace are particularly useful.
#Done

#-----------------------------------------------------------------------------------------------------------------------
# Write a Python program to calculate the length of a string
# my_string = input("Please enter a string: ")
# print("You have entered string:", my_string)
# print("Its length is: ", len(my_string))

#-----------------------------------------------------------------------------------------------------------------------
# Write a Python program to count the number of characters (character frequency) in a string.
# Expected Result : {'o': 3, 'g': 2, '.': 1, 'e': 1, 'l': 1, 'm': 1, 'c': 1}
# my_string = input("Please enter your string: ")
# letter_count = {}
# index = 0
# for letter in my_string:
#     if letter.lower() in letter_count:
#         letter_count[letter.lower()] += 1
#     else:
#         letter_count[letter.lower()] = 1
#
# print(letter_count)

#-----------------------------------------------------------------------------------------------------------------------
# Define a function that computes the length of a given list or string. (It is true that Python has the len()
# function built in, but writing it yourself is nevertheless a good exercise.)
my_string = input("Please enter a string for length count: ")




















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