Understanding Python String startswith()

The Python startswith() string method is used to check if a specified string starts with a given prefix/substring or not. It is an inbuilt string function in Python.

• The startswith() method returns true if the the string starts with the prefix that we are looking for and if it doesn't have that prefix then, in that case, this function returns false.
• The parameter prefix of this function is case sensitive, which means study and Study are two different prefix values.

Below we have a basic syntax of the startswith() method in Python:

str.startswith(prefix, beg=0,end=len(string))

Python String **startswith()**: Parameters

The description of the Parameters of startswith() is given below:

• prefix

  This parameter is used to specify the substring which is the prefix.

• start

  It is an optional parameter that is used to set a starting index for the matching boundary.

• end

  It is also an optional parameter that is used to set the ending index of the matching boundary.

Python String **startswith()**: Returned Values

For the returned value there are two cases:

• It returns true in the case if the string starts with a specified prefix or substring
• It returns false in the case if the string does not start with a specified prefix.

Below we have an example to show the working of the startswith() function in python:

strA = 'Welcome to StudyTonight'
print(strA.startswith('Study'))

The output of the above code snippet will be:

True

Let us see another code snippet where we see the case-sensitiveness of this method:

strA = 'Welcome to StudyTonight'
print(strA.startswith('study', 10))

The output of the above code snippet will be:

false

Note: As startswith() is a case sensitive function, study and Study are treated as different strings, and hence we got false as output of the above code.

In this tutorial, we have discussed the startswith() method of strings in Python which is used to check if the specified string starts with a given prefix or not.