Python Program to Convert List to String

The programmers may encounter situations where certain instructions are to be written either a line that commands or a CSV file or a text file. Strings are the best choice to accomplish this task. However, programmers tend to use a data structure such as lists in their programs to ensure the iteration of values or texts. To convert the list of items into a text manner, it should be converted to a string. In this article, let’s understand a thin line of distinction between the lists and strings in Python before we dive deeper into the task of answering “How to convert a list to string in Python?”.

What Is A List?

A list in Python is a sorted, flexible collection of data objects. In contrast to an array, which may only include objects of one kind, a list can contain various things.

To store many pieces of data simultaneously in Python, utilise lists. For illustration

Let’s say we have to write down the roll numbers of 10 students. We can build a list instead of creating 10 different variables unnecessarily.

What Is A String?

In Python, a string is a data type comprising several characters. Letters, numerals, and even special characters are all permitted.

A string cannot be changed once formed because it is an immutable data type. The storage and manipulation of text data, and the representation of names, addresses, and other information that can be represented as text, are all common uses for strings.

Why Convert List To String Python?

• You must format the data in a specific way when writing output to the console or a file. Using string manipulation methods, we can quickly prepare the result when we convert a list to a string.
• It is preferable to send or save data as a string rather than a list for storage or transmission. A list of names, for instance, can be converted to a string before being saved if you wish to put it in a file or database. Transforming the list into a string is preferable to correctly transferring data across a network.
• It can be simpler to convert two lists to strings first, then compare the strings if you wish to compare two lists.
• Some APIs or libraries demand that data be supplied as a string rather than a list.

Differences between string and list in Python

A string in Python is a sequence of Unicode characters, whereas a list is the ordered sequence of elements of the same type. Values in a string cannot be modified, whereas the elements of a list can be modified. Hence, lists are said to be mutable, whereas strings are an immutable sequence of characters. The string stores only ‘char’ type data, whereas the lists can store all alphanumeric characters. Adding and removing value is not supported in strings, whereas lists allow the addition and deletion of elements as per the user convenience. 

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Popular Techniques To Change List To String Python

1. Using a loop

• Python allows you to turn a list of objects into a string by iterating through each item and adding it to the end of the string. This method is not recommended since a new string gets created every time an object is attached.
• Only use this method to study how lists in Python can be converted to strings because it is slow, and there are several other efficient ways to achieve conversion. The example is as follows:

Example:

variable1 = ["Python", "is", "an", "object", "oriented","programming","language"]

variable2 = ""

for k in variable1:

       variable2 += str(k)+ "  " 

print(variable2)

Output:

"Python is an object-oriented programming language."

2. Using join()

• join() is the second most popular way to convert a list to a string. It accepts iterable as input and joins them before returning the output.
• The syntax of join() is depicted as “string.join(iterable)”.

3. Using map()

• Python uses the map() method to change list to string Python as another way. When an integer value is present in the iterable, in this instance, a list, this method is used.
• Since the join() method can only accept strings as inputs, we utilise the map() method to turn the integer values into strings before turning the list into a string.
• The syntax of map() is depicted as “map(func, iterables)”.

Furthermore, if you want to convert string to array python, you can use the split(), inner.split(), splitlines() and the reader() method to do so. 

Conversion of List to String in Python

There are several ways in which the user can convert a list to a string in Python. Let’s look at a few of them with examples.

Case 1: A list with alphabetic characters as its constituent elements. 

In this case, the Python join() method can be used to convert the list of items to a string, as shown in the code below. 

The output of the above code is as follows:

welcome to, python, blog

welcome to

python

blog

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Case 2: A list with non-string elements

The method discussed in Case 1 is the simplest method to convert a list with only string characters into a string. However, this method may not be suitable if the list constitutes non-string elements such as numbers. Let us consider a list of integers that is to be obtained as a comma-separated string. The code written below can accomplish this task easily.

The output of the above code is as follows:

1000, 154, 4528, 8457

If the object of the list contains a square bracket pair, the print statement can be replaced as shown below. However, the output of the code remains the same.

In the last, the map() function can be used to convert each element of the list into a character string and then it can be joined. 

The output with the two print statements will look like this:

1000, 154, 4528, 8457

1000

154

4528

8457

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Case 3: A list that contains both string characters and integers

The implementation of the conversion of the list to string in Python, in this case, can be accomplished as mentioned in the code below. 

The output of the above code is as follows:

Joined String: This is a sample program in Python

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Writing the item’s list into a CSV or text file:

There is a standard write() method that enables the Python interpreter to write a single line of data into a file. If multiple lines are to be written, the writelines() function can be used. Let us see the use of these functions with an example. 

The output of the above code is as mentioned below.

The use of the ‘n’ keyword can enable to get an output with a break after each list item. The implementation of this in the Python program is shown below.

The output will now look like this.

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