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Python str() Function Explained

The Python str() function converts a value into a string.

A string is text in Python. Beginners often use str() when they need to turn a number into text before combining it with other strings.

Quick example #

age = 25
text = str(age)

print(text)
print(type(text))

Output:

25
<class 'str'>

Use str() when you need a string version of a value, such as a number before joining or concatenating text.

What str() does #

str() converts a value into a string.

That means:

  • An integer like 10 becomes "10"
  • A float like 3.14 becomes "3.14"
  • A boolean like True becomes "True"
  • A list like [1, 2, 3] becomes "[1, 2, 3]"

The result is text, so you can:

  • print it
  • combine it with other strings
  • save it to a file
  • use it in messages

Basic syntax #

The basic syntax is:

str(object)

Here, object is the value you want to convert.

str() always returns a string.

A very common beginner use case is converting a number before combining it with text:

score = 100
message = "Your score is " + str(score)

print(message)

Output:

Your score is 100

If you are not sure what type a value has, the type() function can help you check.

Simple examples #

Convert an integer to a string #

number = 10
text = str(number)

print(text)
print(type(text))

Output:

10
<class 'str'>

Convert a float to a string #

price = 3.14
text = str(price)

print(text)
print(type(text))

Output:

3.14
<class 'str'>

Convert a boolean to a string #

value = True
text = str(value)

print(text)
print(type(text))

Output:

True
<class 'str'>

Convert a list to a string #

items = [1, 2, 3]
text = str(items)

print(text)
print(type(text))

Output:

[1, 2, 3]
<class 'str'>

This gives you the string form of the list. It does not join the items into a clean sentence.

When to use str() #

Use str() when you want a text representation of another data type.

Common cases:

  • Before concatenating text with numbers
  • Before writing mixed values to a file
  • Before displaying values in messages
  • When you want text instead of a numeric value

Example:

name = "Maya"
age = 25

message = name + " is " + str(age) + " years old."
print(message)

Output:

Maya is 25 years old.

If you need help with cleaner message building, see how to format strings in Python.

str() vs print() #

These two functions do different jobs:

  • str() converts a value and returns a string
  • print() displays output on the screen

Example:

value = 42

text = str(value)
print(text)
print(type(text))
print(type(value))

Output:

42
<class 'str'>
<class 'int'>

Notice:

  • str(value) created a string
  • print() only displayed values
  • print() did not change value from int to str

You can learn more about output with the print() function.

str() vs repr() for beginners #

For beginners, the main idea is simple:

  • str() is the more readable text version
  • repr() is more developer-focused

In everyday beginner code, you will usually need str() much more often.

For example, when showing values in a message, str() is usually the right choice.

Common beginner mistakes #

Thinking str() changes the original variable #

str() does not modify the original value. It returns a new string.

age = 25
text = str(age)

print(age)
print(type(age))
print(text)
print(type(text))

Output:

25
<class 'int'>
25
<class 'str'>

Forgetting to store the result #

This works:

age = 25
text = str(age)

But if you only do this:

age = 25
str(age)

the conversion happens, but you did not save the result anywhere.

Using str() too early #

If you convert a number to a string, you can no longer use it directly for math.

price = 10
text_price = str(price)

# print(text_price + 5)   # This would cause an error

If you need a number again, convert it back with int() or float(), depending on the situation.

Expecting str(list_value) to create user-friendly formatting #

This:

items = ["apple", "banana", "orange"]
print(str(items))

prints:

['apple', 'banana', 'orange']

That is the string representation of the list. It is not the same as a nicely formatted sentence.

Return value #

str() returns a new string.

Important points:

  • It always returns a string
  • It does not modify the original object
  • You can use type() to confirm the result

Example:

value = 99
converted = str(value)

print(converted)
print(type(converted))

Output:

99
<class 'str'>

Common causes of confusion #

Beginners usually run into trouble with str() for these reasons:

  • Trying to add a string and an integer without conversion
  • Confusing conversion with printing
  • Using str() too early and then trying to do math on the result
  • Assuming list or dictionary conversion creates user-friendly formatting

A very common related error happens when you try to combine text and a number directly. If that is your problem, see how to fix TypeError: can only concatenate str not int to str.

Useful debugging steps #

If you are not sure what is happening, print both the value and its type:

value = 25

print(value)
print(type(value))

converted = str(value)
print(converted)
print(type(converted))

This helps you see exactly when a value changes from int, float, or another type into str.

FAQ #

What does str() return in Python? #

It returns a string version of the value you pass in.

Does str() change the original variable? #

No. It creates and returns a new string.

Can str() convert numbers to text? #

Yes. It can convert integers, floats, and other values into strings.

Why use str() before combining text and numbers? #

Because Python does not let you directly concatenate a string with an integer or float.

Is str() the same as print()? #

No. str() converts to text. print() shows output.

See also #

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