str() — Convert to String

str() converts every fundamental type in this module into text.

Unlike int(), float(), and complex(), converting to string is straightforward — you can convert integers, floats, booleans, and complex numbers without errors.

What you'll learn

• Convert int, float, bool, and complex into strings
• Understand the difference between print() and repr()
• Use str() for concatenation and display
• Learn why converting back follows different rules

What does str() do?

str() converts a value into a string.

text = str(value)

The result is always of type str, regardless of the original type.

Example 1 — Integer → String

a = 100
b = str(a)

print(a, type(a))
print(b, type(b))
print(repr(b))

100 <class 'int'>
100 <class 'str'>
'100'

Why two different outputs?

• print(b) displays the text without quotes.
• repr(b) shows the actual string representation with quotes.

Example 2 — Float → String

a = 12.34
b = str(a)

print(b)
print(repr(b))

12.34
'12.34'

The decimal digits are preserved in the string.

Example 3 — Boolean → String

print(str(True))
print(repr(str(True)))

True
'True'

This creates the text "True", not the boolean value True.

Example 4 — Complex → String

a = 2 + 3j

print(str(a))
print(repr(str(a)))

(2+3j)
'(2+3j)'

Notice the parentheses — they are part of Python’s string representation for complex numbers.

Interactive playground

Select a value and see how str() converts it.

Conversion map

Every conversion below is valid.

Original type	Example	String result
int	str(100)	'100'
float	str(12.34)	'12.34'
bool	str(True)	'True'
complex	str(2+3j)	'(2+3j)'

Why str() matters

Strings are required for concatenation.

Incorrect

# "Score: " + 100

TypeError: can only concatenate str (not "int") to str

Correct

message = "Score: " + str(100)
print(message)

Score: 100

Round-trip reminder

Converting to string is easy. Converting back depends on the matching function.

Original	After str()	Can convert back?
100	"100"	Yes — int()
12.34	"12.34"	Yes — float()
True	"True"	No — int() fails
2+3j	"(2+3j)"	No — int() fails; use complex()

Practice exercises

Exercise 1 — Convert these values into strings.

str(100)
str(12.34)
str(True)
str(2+3j)

Print the value and its type.

Exercise 2 — Build this message:

"Mul=" + str(3.5)

Expected output: Mul=3.5

Exercise 3 — Predict before running:

int(str(True))

Will it succeed or raise an error?

Quick knowledge check

1. Does str() work for all four types?
   Yes. It converts int, float, bool, and complex into text.

2. What is str(True)?
   'True' (a string)

3. What is str(2+3j)?
   '(2+3j)'

Summary

• str() converts all fundamental types into strings.
• print() displays text without quotes; repr() reveals the actual string.
• Use str() for concatenation, logging, or displaying values.
• Converting back requires the matching caster (int(), float(), or complex()), and not every string can be parsed.

Next module: Operators and Expressions — how values combine after you have the right types.