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Let's see a simple way to convert a list to a string in Python using the .join() method as follows:
1cool_names = ["Danny", "Peter", "Johanna"] 2 3print(", ".join(cool_names)) #Output: Danny, Peter, Johanna
This is the most simple way to convert a list to a string in Python, in the following sections we will describe how the .join() method works, as well as check other ways to convert a list to a string in Python.
🔗 If you need more knowledge on python lists, here is a great article.
The join method is quite simple, it takes an iterable (in this case it would be our list), which joins each element of our list and returns these elements as a string. This method is usually used together with a separator, which as we saw in the previous example was ”, “. Basically, to use this method, we just have to pass our list as an iterable together with the separator we want to use, like this ”separator”.join(list_name). Let's see another example of how to use the join() method as follows:
1pets = ["Dog", "Cat", "Parrot", "Hamster"] 2 3string_pets = " ".join(pets) #This is joining the elements of our list and separating them with a space 4 5print(string_pets) #Output: Dog Cat Parrot Hamster
It is important to mention that the iterable only takes string type values. If we have a list with any int, we'll have an error:
1list1 = ["Hello", "People", 1, 9, "Greet"] 2 3string_list1 = ", ".join(list1) 4 5print(string_list1) #Output: TypeError: sequence item 2: expected str instance, int found
See that we received a TypeError since this method only takes string values, not int values. If we need to convert a list with strings and int values, we should use the following method.
Since we now know that we can only use the .join() method for lists with only type string elements, we can use a second method, in this case, the .map() method, so that, together with the .join() method, can convert a list that has elements of type both string and int. Let's see an example below:
1list1 = ["Hello", "People", 1, 9, "Greet"] 2 3string_list1 = ", ".join(map(str, list1)) 4 5print(string_list1) #Output: Hello, People, 1, 9, Greet
The .map() method takes two parameters that are a function and an iterable (.map(function, iterable)), where the function would be the str function that will convert any element into a string and the iterable, as we already know, will be our list. Basically, we are using the .map() method to first convert the int elements of our list into string elements before converting the whole list into a string.
Another useful way to use the .join() method with lists that have int type elements is by using list comprehension. This is a feature that would help us convert a list with both string and int elements into a whole new string. To use this feature, we need to use a for loop to iterate through each element of the list, to then use the list comprehension feature alongside the .join() method to finally convert the list to a string. This option should look like this ”separator”.join([str( elements ) for elements in list_name]). Let's see an example below:
1list1 = ["Hello", "People", 1, 9, "Greet"] 2 3string_list1 = ", ".join([str( elements ) for elements in list1]) 4 5print(string_list1) #Output: Hello, People, 1, 9, Greet
Our last "trick" to convert any list to string in Python is by just iterating through the elements of a list and concatenating the same in a new string variable, this is done by using a for loop. The "trick" here is to declare an empty string variable since we'll use the for loop to append each list element to our empty string variable. This should look like this:
1pets = ["Dog", "Cat", "Parrot", "Hamster"] 2 3string_list1 = "" 4 5for element in pets: 6 string_list1 = string_list1 + " " + element 7 8print(string_list1) #Output: Dog Cat Parrot Hamster
Be advised that this option only works with lists that have string elements. If we have an int element in the list, we will get the same error as just using the .join() method with int elements (shown in the third example).
We saw 4 ways how to convert a list to a string in Python in this article, let's see a brief recap so you can master these options:
.join(). You can use this method with lists that have only string elements, the syntax would be ”separator”.join(list_name)..join() and .map(). We use .map() alongside the .join() method to convert a list with string and int type elements into a string. The syntax would be ”separator”.join(map(str, list_name))..join() with List Comprehension. Can be used with lists that have both string and int elements. This option should look like this ”separator”.join([str( elements ) for elements in list_name])We hope this article helps better understand how to convert list to string in Python.