{"id":12044,"date":"2020-10-14T22:27:42","date_gmt":"2020-10-15T05:27:42","guid":{"rendered":"https:\/\/careerkarma.com\/blog\/?p=12044"},"modified":"2023-12-01T04:01:34","modified_gmt":"2023-12-01T12:01:34","slug":"python-substring","status":"publish","type":"post","link":"https:\/\/careerkarma.com\/blog\/python-substring\/","title":{"rendered":"Python Substring: A Step-By-Step Guide"},"content":{"rendered":"\n

A Python substring is a portion of text taken from a string. You can extract a substring in Python using slicing, with the format: YourString[StartingIndex:StoppingIndex:CharactersToSkip].<\/em><\/p>\n\n\n\n

\n\n\n\n

Often, programmers have data that they want to split up into different parts. For example, a developer may have the full name of a user, and only need to get their first name. In this case, the developer would want to split up the name into two parts: forename and surname.<\/p>\n\n\n\n

How do you accomplish this in the Python programming language? That\u2019s where string slicing<\/em> comes into play. Using a technique called slicing<\/em>, we can get a specific part of a string, which then becomes a substring<\/em>. In this tutorial, we are going to break down how substrings work in Python, and how you can use slicing to create your own.<\/p>\n\n\n\n

String Indexes: A Refresher<\/h2>\n\n\n\n

Before we go on to discuss slicing and the slice syntax, we must first look at how Python strings<\/a> are indexed.<\/p>\n\n\n\n

In Python, a string is a sequence of one or more characters that could include numbers, spaces, letters, or symbols. You can access parts of a string in the same way that you would with other sequences, like a list.<\/p>\n\n\n\n

Each character in a string has its own index value<\/a>, which states the location of the character in the string. These numbers start with the index number 0. For example, here is how the string Python Substrings<\/em> would be represented:<\/p>\n\n\n\n
P<\/td>y<\/td>t<\/td>h<\/td>o<\/td>n<\/td>
<\/td>		S<\/td>u<\/td>b<\/td>s<\/td>t<\/td>r<\/td>i<\/td>n<\/td>g<\/td>!<\/td><\/tr>
0<\/td>1<\/td>2<\/td>3<\/td>4<\/td>5<\/td>6<\/td>7<\/td>8<\/td>9<\/td>10<\/td>11<\/td>12<\/td>13<\/td>14<\/td>15<\/td>16<\/td><\/tr><\/tbody><\/table>\n\n\n\n

The first character in our string (P<\/em>), has the index value of 0. The ! character<\/em> has an index value of 16.<\/p>\n\n\n\n

Because each character has its own index number, we are able to read and change individual characters in our strings.<\/p>\n\n\n\n

Python String Substring<\/h2>\n\n\n\n

Let\u2019s say that we want to get the first three characters from a string\u2014how do we do it? Or what if we want to retrieve the last two characters in a string?<\/p>\n\n\n\n

We can use a technique called slicing to retrieve particular pieces of data from a string. This is where we specify sequence of characters from a certain string that we want to retrieve. We can use slices to get any data we want from a string. The syntax we use is:<\/p>\n\n\n\n

string[start:end:step]<\/pre><\/div>\n\n\n\n
There are three components to a slice:<\/p>\n\n\n\n