Python - Convert String to Boolean - Data Science Parichay

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 –

# string to boolean
bool(s)

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))

Output:

True

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))

Output:

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False

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))

Output:

True
True

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.

Let’s look at an example.

# 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))

Output:

True
False

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))

Output:

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.

Author

Piyush Raj

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.

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