Python – String till Substring

Sometimes, more than finding a substring, we might need to get the string that is occurring before the substring has been found. Let’s discuss certain ways in which this task can be performed.

Method #1 : Using partition()

The partition function can be used to perform this task in which we just return the part of the partition occurring before the partition word.

Python3

# Python3 code to demonstrate
# String till Substring
# using partition()

# initializing string
test_string = "GeeksforGeeks is best for geeks"

# initializing split word
spl_word = 'best'

# printing original string
print("The original string : " + str(test_string))

# printing split string
print("The split string : " + str(spl_word))

# using partition()
# String till Substring
res = test_string.partition(spl_word)[0]

# print result
print("String before the substring occurrence : " + res)

Output : 

The original string : GeeksforGeeks is best for geeks
The split string : best
String before the substring occurrence : GeeksforGeeks is

Method #2 : Using split()

The split function can also be applied to perform this particular task, in this function, we use the power of limiting the split and then print the former string. 

Python3

# Python3 code to demonstrate
# String till Substring
# using split()

# initializing string
test_string = "GeeksforGeeks is best for geeks"

# initializing split word
spl_word = 'best'

# printing original string
print("The original string : " + str(test_string))

# printing split string
print("The split string : " + str(spl_word))

# using split()
# String till Substring
res = test_string.split(spl_word)[0]

# print result
print("String before the substring occurrence : " + res)

Output : 

The original string : GeeksforGeeks is best for geeks
The split string : best
String before the substring occurrence : GeeksforGeeks is

Method #3 : Using find()

Python3

# Python3 code to demonstrate
# String till Substring
# using find()
# you can also use index(0 instead of find()

# initializing string
test_string = "GeeksforGeeks is best for geeks"

# initializing substring
spl_word = 'best'

# printing original string
print("The original string : " + str(test_string))


# String till Substring
x=test_string.find(spl_word)
res=test_string[0:x]


# print result
print("String before the substring occurrence : " + res)

Output

The original string : GeeksforGeeks is best for geeks
String before the substring occurrence : GeeksforGeeks is