Solution Exercise 73: Python algorithme which determines the List of position of a pattern in a given Texte

Exercise 73

Write a function which takes as parameter a variable of type string s and another string T, and returns the list of positions of a pattern s in the string T. The function must return the empty list if the pattern s does not appear in the text T.

Solution

#function which determines the list of positions of s in the text T
def listPositions (T, s):
    # initializing the list of s occurrences in T
    lPosition = []
    for i in range (0, len (T)):
        # we test if the occurrence s is at position i
        if T [i: len (s) + i] == s:
            lPosition.append (i)
    return lPosition
# Example
T = "Python is the most popular language and the most used language"
s = 'most'
print (listPositions (T, s)) # output: [14, 44]