Python - String startswith() Method

The startswith() method available to string objects determines if a string object starts with a specific string value or not and if it does, the bool value True is returned, else the bool value False is returned.

Signature of startswith() method

startswith(value, start, end)

Parameters	Description
value	This is a string value, which is searched in the invoked string. A non-optional attribute.
start	This is an integer value to specify the index position(zero-based index) to start the search at. An optional attribute.
end	An integer value to specify the index position(one-based index) to end the search at. An optional attribute.

startswith() example

Hello World

# Python - Example of startswith() method.



# Creating a string 
s1 = 'Hello World'


# Printing the value of string 
print('String is : ', s1)


# Checking if the string starts with the value 'He'
b1 = s1.startswith('He')

print('Does ', s1 , ' starts with He ? ', b1)


# Checking if the string starts with the value 'Hello'
b2 = s1.startswith('Hello')

print('Does ', s1 , ' starts with Hello ? ', b2)


# Checking if the string starts with the value 'World'
b3 = s1.startswith('World')

print('Does ', s1 , ' starts with World ? ', b3)

Output is :

String is :  Hello World
Does  Hello World  starts with He ?  True
Does  Hello World  starts with Hello ?  True
Does  Hello World  starts with World ?  False

Program Analysis

In the first comparison, startswith() method returns true, as the string object Hello World starts with a string value, He.
In the second comparison, startswith() method returns true, as string object Hello World starts with a string value, Hello.
In the last comparison, startswith() method returns false, as string object Hello World doesn't start with a string World, it rather ends with it.

Method startswith() is case-sensitive.

startswith()

# Python - Example of startswith() method.


# Creating a string 
s1 = 'World Peace'


# Printing the value of string 
print('String is : ', s1)



# Checking if the string starts with the value 'World'
b1 = s1.startswith('World')

print('Does ', s1 , ' starts with World ? ' , b1)  



# Checking if the string starts with the value 'world'
b2 = s1.startswith('world')

print('Does ', s1 , ' starts with world ? ', b2)



# Checking if the string starts with the value 'WORLD'
b3 = s1.startswith('WORLD')

print('Does ', s1 , ' starts with WORLD ? ', b3)

Output is :

String is :  World Peace
Does  World Peace  starts with World ?  True
Does  World Peace  starts with world ?  False
Does  World Peace  starts with WORLD ?  False

Program Analysis

World Peace

In the first comparison, startswith() method returns true, as the string object starts with World.
In the second comparison, startswith() method returns false, as string object does not start with world with lower case w.
In the last comparison, startswith() method returns false, as string object doesn't start with upper case WORLD.

Another example of startswith() method

In the upcoming example, we are going to call the startswith() with two optional parameters start and end.

# Python - Example of startswith() method.


# Creating a string 
s1 = 'Always think positive!'



# Checking if the string has a value 'always', starting at index 0 and ending at 15
# which is true because the value 'always' starts at index 0
b1 = s1.startswith('Always', 0, 15)

print(b1)


# Checking if the string has a value 'think', starting at index 7 and ending at 20
# which is true because the value 'think' starts at index 7
b1 = s1.startswith('think', 7, 20)

print(b1)  



# Checking if the string starts with the value 'ways', starting at index 2 and ending at 10
# which is true because the value 'ways' starts at the index 2
b2 = s1.startswith('ways', 2, 10)

print(b2)



# Checking if the string starts with the value 'positive, starting at index 5 and ending at index 10
# which is false because the value 'positive' does not start at the index 5
b3 = s1.startswith('positive', 5, 10)
print(b3)

Output is :

True
True
True
False

Program Analysis

Always think positive!

In the first search, startswith() method returns True, as the invoked string object has the value always, which starts at index 0 and ends before index 15.
In the second comparison, startswith() method returns false, as the invoked string object has the value think, which starts at index 5 and ends before index 20.
In the third comparison, startswith() method returns true, as the invoked string object has the value ways, which starts at index 2 and ends before index 10.
In the fourth comparison, startswith() method returns false, as the invoked string object does not have the value positive, which starts at index 5 and ends before index 10.