How to join two strings to convert to a single string in Python?

In Python, we can join two strings into one single string using different approaches. Each method has its own advantages depending on the use case.

Using + Operator

The most common way to combine two strings is by using the + operator. It concatenates strings exactly as they are, without any automatic separator ?

str1 = "Hello"
str2 = "World"

# Direct concatenation without space
result1 = str1 + str2
print("Without space:", result1)

# Adding space manually
result2 = str1 + " " + str2
print("With space:", result2)

Without space: HelloWorld
With space: Hello World

Using join() Method

The join() method is efficient when combining multiple strings with a separator. Place the strings in a list and specify the separator ?

str1 = "Hello"
str2 = "World"

# Join with space
result1 = " ".join([str1, str2])
print("With space:", result1)

# Join without separator
result2 = "".join([str1, str2])
print("Without separator:", result2)

# Join with custom separator
result3 = "-".join([str1, str2])
print("With dash:", result3)

With space: Hello World
Without separator: HelloWorld
With dash: Hello-World

Using f-strings (Recommended)

F-strings provide the most readable way to combine strings by embedding variables directly within curly braces ?

str1 = "Hello"
str2 = "World"

result = f"{str1} {str2}"
print(result)

# More complex formatting
name = "Alice"
age = 25
message = f"{str1} {str2}, I'm {name} and I'm {age} years old"
print(message)

Hello World
Hello World, I'm Alice and I'm 25 years old

Using format() Method

The format() method uses curly braces as placeholders and is compatible with older Python versions ?

str1 = "Hello"
str2 = "World"

result = "{} {}".format(str1, str2)
print(result)

# With positional arguments
result2 = "{1} {0}".format(str1, str2)
print("Reversed order:", result2)

Hello World
Reversed order: World Hello

Using % Formatting (Legacy)

The percent formatting uses %s placeholders and is mainly used for compatibility with older code ?

str1 = "Hello"
str2 = "World"

result = "%s %s" % (str1, str2)
print(result)

Hello World

Performance Comparison

Conclusion

For modern Python development, use f-strings for their readability and performance. Use join() when combining many strings with separators, and the + operator for simple two-string concatenation.