{"id":2560,"date":"2020-01-13T20:16:36","date_gmt":"2020-01-13T20:16:36","guid":{"rendered":"https:\/\/www.askpython.com\/?p=2560"},"modified":"2022-08-06T13:17:32","modified_gmt":"2022-08-06T13:17:32","slug":"python-concatenate-string-and-int","status":"publish","type":"post","link":"https:\/\/www.askpython.com\/python\/string\/python-concatenate-string-and-int","title":{"rendered":"Python – Concatenate string and int"},"content":{"rendered":"\n

In Python, we normally perform string concatenation using the +<\/code> operator. The +<\/code> operator, however as we know, is also used to add integers or floating-point numbers.<\/p>\n\n\n\n

So what would happen if we have a string<\/em> and an int<\/em> on both sides of the operand?<\/p>\n\n\n\n

Since Python is a dynamically typed language, we would not face any error during compilation, but rather, we get a Runtime Error<\/strong>. (More specifically, a TypeError<\/strong> exception is raised)<\/p>\n\n\n\n

The below snippet proves this:<\/p>\n\n\n

\na = "Hello, I am in grade "\n\nb = 12\n\nprint(a + b)\n<\/pre><\/div>\n\n\n
Output<\/p>\n\n\n
\nTraceback (most recent call last):\n  File "concat.py", line 5, in <module>\n    print(a + b)\nTypeError: can only concatenate str (not "int") to str\n<\/pre><\/div>\n\n\n
So, since we cannot directly concatenate an integer with a string, we need to manipulate the operands so that they can be concatenated. There are multiple ways of doing this.<\/p>\n\n\n\n
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1. Using str()<\/h2>\n\n\n\n
We can convert the integer to a string, via the str()<\/code> function. Now, the new string can now be concatenated with the other string to give the Output;<\/p>\n\n\n
\nprint(a + str(b))\n<\/pre><\/div>\n\n\n
Output<\/strong><\/p>\n\n\n
\nHello, I am in grade 12\n<\/pre><\/div>\n\n\n
This is the most common way to convert an integer to a string.<\/p>\n\n\n\n
But, we can use other methods as well.<\/p>\n\n\n\n
2. Using format()<\/h2>\n\n\n
\na = "Hello, I am in grade "\n\nb = 12\n\nprint("{}{}".format(a, b))\n<\/pre><\/div>\n\n\n
The output remains the same as before.<\/p>\n\n\n\n
3. Using ‘%’ format specifier<\/h2>\n\n\n
\na = "Hello, I am in grade "\n\nb = 12\n\nprint("%s%s" % (a, b))\n<\/pre><\/div>\n\n\n
While we can specify that both a<\/code> and b<\/code> are strings, we can also use C-style format specifiers (%d<\/code>, %s<\/code>) to concatenate an integer with a string.<\/p>\n\n\n
\nprint('%s%d' % (a,b))\n<\/pre><\/div>\n\n\n
The output remains the same for the above code.<\/p>\n\n\n\n
4. Using f-strings<\/h2>\n\n\n\n
We can use Python f-strings on Python 3.6 or above to concatenate an integer with a string.<\/p>\n\n\n
\na = "Hello, I am in grade "\n\nb = 12\n\nprint(f"{a}{b}")\n<\/pre><\/div>\n\n\n
5. Printing the string using print()<\/h2>\n\n\n\n
If we want to directly print the concatenated string, we can use print()<\/code> to do the concatenation for us.<\/p>\n\n\n
\na = "Hello, I am in grade "\nb = 12\nprint(a, b, sep="")\n<\/pre><\/div>\n\n\n
We join a<\/code> and b<\/code> using a null string separator (sep<\/code>), since the default separator for print()<\/code> is a space (” “).<\/p>\n\n\n\n
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Conclusion<\/h2>\n\n\n\n
In this article, we learned how to concatenate an integer to a string using various methods.<\/p>\n\n\n\n
References<\/h2>\n\n\n\n