Python

Python string comparison

In Python, a string is a series of characters; each character contains a different Unicode or ASCII value. No Python variable has a definite data type when it comes to numbers, strings, or characters. A character is also considered a string. An easy way of comparing strings is that the characters are compared against both strings. If distinct characters are found, then we have to compare their Unicode values are well. The characters having greater Unicode values are considered as greater value characters. For comparison of two strings, there is no special way. If we directly compare the values of strings, we use the ‘==’ operator. If strings are identical, it returns True, otherwise False.

There are diverse comparison operators who are utilized to equate the strings in python. We start with == and != Operator and then discuss more comparison operators with the help of examples.

Use == and != operator for comparing two strings:

Comparison of two strings can be done efficiently by using the (==) and (!=) operators. If the strings are equal, it shows a true result otherwise false. For the execution of codes of python, we have spyder5 installed on the laptop. First, a new project is created after tapping the “new file” button from the menu bar.

In this program, we take a string value in a language variable. Now we contrast strings with the (==) and (!=) operator.

In this code, Language is a variable that contains the string “chinese”. The comparison is done by comparing the characters in one string with the other in a row. Now, let’s run the code by pressing the F5 button.

As an output, the operator equal to (==) returns True, and the operator not equal to (! =) returns False. In this program, we are going to do a comparison between uppercase and lowercase characters. We use the ord() function in this code. Characters with a smaller Unicode value are small, and characters with a greater Unicode value are large.

So, in this instance, we compare “c” of “chinese” with “C” of Chinese.

As the string “chinese” and “Chinese” are not the same. So print statement returns false after comparing these strings by (==) operator. After finding out the Unicode values of “c” and “C” we conclude that the Unicode value of “C” is smaller than “c”. “chinese” is greater than “Chinese”. So print statement returns true.

Compare the strings with other operators:

Apart from the (==) and (!=) operator, many other operators are used to compare strings in python.

In this example, we use these operators ((<), (>), (<=), (>=)) to compare the strings.

We suggest the “chinese” value to a string and the “china” value to string1. Now we compare these two strings with the help of “<, >, <=, >=” operators. After comparing string and string1 by the “<" operator, the print statement returns false or true.

As the first four alphabets of “chinese” and “china” are alike. The fifth character of the string is “e”; however, the fifth character of string1 is “a”. The Unicode value of “e” is 101, and “a” is 97. After comparing these values, “chinese” is greater than “china”. So, according to this, the print statement returns true or false.

Compare the strings with ‘is’ Operator:

The comparison for the type of the two objects is done by “is operator”. If two variables point to a similar object, it will return True; else, it will return False. False may be returned even if both strings have the same value but different object IDs.

In this example, we take three strings which are: “string1, string2, string3”. We take “u, v, w” as the value of string1. The values of string1 and string2 are the same. The values of String1 are assigned to string3. Now the strings are compared by “== and is” operators.

string1 and string2 are identical, which means that these strings have similar objects. We decide on a new object for string3, and the value of string3 is the same as the value of string1. So it means string3 is a distinct object, but string1 and string2 are identical objects.

Addresses of objects are determined by using the id() function. So we use this function to decide the address.

String1 and string2 return True as they have the same value. By comparing String1 and string3 with the “==” operator, it returns true. After that, we use the “is” operator to compare the types of these strings. String1 is string2 returns True while string1 is string3 returns False. In the end, the id() function shows the address of string1, string2, and string3. The address of string1 and string2 is identical. The address of string3 is distinct.

Comparing the strings with User Input:

In this method, we take Input from the user and perform different comparison operations on them.

Here we take three strings named “str_1, str_2, str_3”. The values of str_1 and str_2 are entered by the user. But the value of str_3 is the same as the value of str_1. Now the strings are compared by different comparison operators. Here we use “==, !=, <=, >=” operators to compare these strings.

When we run this program, the user is asked to enter the values of str_1 and str_2. After giving values to the strings, these three strings are compared by different operators.

The entered value of str_1 is “chinese” and str_2 is “china”. First, we compare these strings by the “==” operator, as the values are not the same, so the output is false. Then we compare these strings by the “!=” operator, as the values are not the same, so the result is true.

In the next line, the strings are compared by “=” operator. As str_1 is greater than str_2, so it is true. In the last, we use “is” to compare the strings. Str_1 and str_2 have different values, so the output is false. But the values of str_2 and str_3 are the same, so their result is true.

Conclusion:

In this article, we have talked over different comparison operators for strings in python. These operators are: “= =” operator, “!=” operator, “>” operator, “<” operator, “>=” and “<=” operator. We also explained the dissimilarity between ‘==’ and ‘is’ Operator with examples. The “is” operator is also used for comparison, and it is similar to the (==) operator. ‘Is” operator compares the object ID of the specified string rather than the Unicode value. But the equal to (==) operator compares the Unicode values of strings.

About the author

Kalsoom Bibi

Hello, I am a freelance writer and usually write for Linux and other technology related content