Python string false to bool

how to convert a string to boolean in python

This article discusses a brief introduction of string and boolean datatypes. Lastly, we’ll discuss How to convert a String to Boolean in Python. The string is a derived datatype used to represent a sequence of characters. They are usually declared using quotation marks. You can use both single quotes or double quotes to declare a string.

Strings in Python are not changeable. Once created, they can’t be changed like tuples in Python. Strings are generally used to label information on graphical user interfaces or many other places like that.

On the other hand, Boolean is a built-in data type in Python that return answers in logic types 0/1, Yes/No, or true/False.

Ways to Convert String to Boolean in Python

The most important question is what is the purpose of boolean datatypes? Why do we need to convert a string to boolean. Boolean datatypes can be used to check if the input taken from the user is an empty string or non-empty. They can also be used to check if an input is an instance of a particular datatype or not

There can be several other uses also. We’ll discuss different methods along with their uses to convert a string to boolean expression.

Method 1: Conversion of string to boolean using bool() method

Python provides a builtin bool() function which takes string as an input. If the string is empty, the function returns false. For non-empty strings, it return true.

string = input("Enter a string: ") value = bool(string) if(value): print("The entered value is a string") else: print("The string entered is empty")

Enter a string: Welcome to Entechin The entered value is a string

Now press enter without typing anything, and the code will display the following output on the screen.

The string entered is empty.

Method 2: Conversion of string to boolean using strtobool() method

The distutils.util module provides strtobool() method which can be used to convert a string to a boolean value i.e., 0 or 1.The method only accepts true, false, t, f yes, no, y, n, off values. Any other value except them raises a ValueError. It converts the positive values to 1 such as true, yes etc. and converts negative values such as no, false etc.

The following code demonstrates the use of strtobool() method to convert a string to boolean.

import distutils.util as module input_value = module.strtobool("True") print("Output: ",input_value)

input_value = module.strtobool("False") print("Output: ",input_value)

input_value = module.strtobool("Hi") print("Output: ",input_value)

ValueError: invalid truth value 'hi'

Method 3: Convert a string to a boolean to check if an object is an instance of a particular type

Suppose you’re designing an application where you need an integer. To check whether the input entered by user is an integer or not, you can use boolean datatypes. If you want to know whether an object is an instance of a particular type, you can use the built-in Python function isinstance().

x = int(input("Enter a value: ")) print(isinstance(x,int))

In the above example, the data type of input is an integer. Therefore, the isinstance () returns True, but if the data type is not an integer, it returns False. Similarly, you can also check whether the input entered by the user is a string.

x = "Hello" print(isinstance(x,int))

In the example above, the “Hello” is a string but isintance() method checks whether the value stored is an integer or not. Therefore, the output is false. Now let’s see what happens if we replace int with str.

In this article, a discussion of converting a string to a boolean in Python is presented. There are different methods to do it. Two of them are discussed in detail along with examples. Let us know about your queries in the comments. If you want to learn more about Python Programming, visit Python Programming Articles.

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Python – Convert String to Boolean

In this tutorial, we will look at how to convert a string to a boolean in Python with the help of some examples.

How to convert string to a boolean in Python?

You can use the built-in bool() function to convert a string to a boolean in Python. Pass the string as an argument to the function. The following is the syntax –

It returns True for non-empty string and False for empty strings.

Let’s look at some examples of using the above function.

# create a string s = "cat" # convert to boolean print(bool(s))

We get True as the output because the string s above is non-empty.

Let’s look at another example, this time with an empty string.

# create a string s = "" # convert to boolean print(bool(s))

We get False as the output.

Note that the result from the bool() function depends on whether the passed string is empty or not. So even if you pass truth values in string form, for example, “True” or “False”, you’ll get the same result.

# create string s1 = "True" s2 = "False" # convert to boolean print(bool(s1)) print(bool(s2))

We get True as the output for both the strings.

Convert string truth values to boolean in Python

If you want to convert a string containing truth values such as “True” or “False” to boolean, you can use the equality operator to compare them with “True” and “False” and return a boolean value.

# string to boolean function def str_to_bool(s): if s == "True": return True elif s == "False": return False else: return None # create string s1 = "True" s2 = "False" # string to boolean print(str_to_bool(s1)) print(str_to_bool(s2))

We get True for the string having the value “True” and False for the string having the value “False”.

Alternatively, if you want a more exhaustive match for a string containing truth values like “True”, “1”, “TRUE”, “true”, etc. you can use the membership operator in . Let’s look at an example.

# string to boolean function def str_to_bool(s): if s in ("True", "TRUE", "true", "1"): return True elif s in ("False", "FALSE", "false", "0"): return False else: return None # list of strings s_ls = ["True", "TRUE", "1", "False", "FALSE", "0"] # string to boolean for s in s_ls: print(str_to_bool(s))

True True True False False False

We get True as the output for the string “true”.

Note that the above example is a very specific use case. It all depends on which string values you want to consider as True and which string values you want to consider as False .

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Author

Piyush is a data professional passionate about using data to understand things better and make informed decisions. He has experience working as a Data Scientist in the consulting domain and holds an engineering degree from IIT Roorkee. His hobbies include watching cricket, reading, and working on side projects. View all posts

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Convert String to Boolean in Python

1. Use the bool() Function to Convert String to Boolean in Python
2. Use the distutils.util.strtobool() Function to Convert String to Boolean in Python
3. Use the List Comprehension to Convert String to Boolean in Python
4. Use the map() and Lamda Function to Convert String to Boolean in Python
5. Use the JSON Parser to Convert String to Boolean in Python
6. Use the eval() Function to Convert String to Boolean in Python

In the world of programming, there are many conversions of data types that programmers have to make that best suit their problem statement. One of those data types is the boolean data type with two possible values, true or false.

This tutorial will introduce different ways to convert a string to a boolean value in Python.

Use the bool() Function to Convert String to Boolean in Python

We can pass a string as the argument of the function to convert the string to a boolean value. This function returns true for every non-empty argument and false for empty arguments.

Example 1:

string_value = "Hello" boolean_value = bool(string_value)  print(boolean_value) 

Example 2:

string_value = "" boolean_value = bool(string_value)  print(boolean_value) 

Use the distutils.util.strtobool() Function to Convert String to Boolean in Python

This function converts the string value to 1 or 0. It depends on whether the value is positive or negative. Positive values like True , Yes , and On are converted to 1, and negative values like False , No and Off are converted into 0.

Example:

String_value = distutils.util.strtobool("Yes") print(String_value) 

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Convert String to Boolean in Python: A step-by-step guide

In this article, we will discuss how to convert String to Boolean in Python.

This function is a built-in operation used for handling strings.

Let’s dive into why this function exists and how to use it in both Code & No Code Python.

Why is the String to Boolean function important?

In Data Analytics , there are many data types (string, number, integer, float, double, date, timestamp…) that data teams have to deal with and select the data types that best suit their problem statement.

The boolean data type has only two possible values, true or false.

For instance, you want to know if the status of a given user is Active or not in your product but the dataset is as follows:

Your “Activation Status” column is in String type. So let’s dive into how to handle this and convert this data type.

Convert String to Boolean: The Hard Way by Coding

Method 1: Bool() Function to Convert String to Boolean in Python

The bool() operation takes only one parameter, on which the standard truth testing procedure can be applied.

If no parameter is passed, then False is returned by default.

 CREATE TABLE purchases ( id SERIAL PRIMARY KEY, orderid VARCHAR NOT NULL, orderamount VARCHAR NOT NULL, customerid VARCHAR NOT NULL, quantity VARCHAR NOT NULL, description VARCHAR NOT NULL )  

Method 2: Eval() Function to Convert String to Boolean in Python

If the string is either True or False, Eval() function can also be used.

The Eval() operation can examine the expression argument and assess it as a Python expression.

Method 3: Map() and Lambda Functions to Convert String to Boolean in Python

The Map() function is used when a transformation function is applied to each item in an iteration and a new iteration is formed after the transformation.

The Lambda function is an anonymous function in Python. Whenever an anonymous function is declared in a program, we use the keyword lambda.

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