Python - String Exercises

Example 1

Python program to find number of vowels in a given string.

mystr = "All animals are equal. Some are more equal"
vowels = "aeiou"
count=0
for x in mystr:
   if x.lower() in vowels: count+=1
print ("Number of Vowels:", count)

It will produce the following output −

Number of Vowels: 18

Example 2

Python program to convert a string with binary digits to integer.

mystr = '10101'

def strtoint(mystr):
   for x in mystr:
      if x not in '01': return "Error. String with non-binary characters"
   num = int(mystr, 2)
   return num
print ("binary:{} integer: {}".format(mystr,strtoint(mystr)))

It will produce the following output −

binary:10101 integer: 21

Change mystr to ‘10, 101’

binary:10,101 integer: Error. String with non-binary characters

Example 3

Python program to drop all digits from a string.

digits = [str(x) for x in range(10)]
mystr = 'He12llo, Py00th55on!'
chars = []
for x in mystr:
   if x not in digits:
      chars.append(x)
newstr = ''.join(chars)
print (newstr)

It will produce the following output −

Hello, Python!

Exercise Programs

• Python program to sort the characters in a string
• Python program to remove duplicate characters from a string
• Python program to list unique characters with their count in a string
• Python program to find number of words in a string
• Python program to remove all non-alphabetic characters from a string