Learn Python
String Formatting
Python string formatting is a powerful way to format strings in Python. It allows you to insert values into strings and format the strings in a variety of ways.
Basic string formatting
To format a string in Python, you use the % operator. The % operator is followed by a format specifier, which tells Python how to format the value.
Example:
Python
name = "Alice"
age = 25
# Format the string using the %s format specifier
formatted_string = "Hello, %s! You are %s years old." % (name, age)
print(formatted_string)
Output:
Hello, Alice! You are 25 years old.
Named string formatting
Python also supports named string formatting. Named string formatting allows you to insert values into strings using named placeholders.
Example:
Python
name = "Alice"
age = 25
# Format the string using named placeholders
formatted_string = f"Hello, {name}! You are {age} years old."
print(formatted_string)
Output:
Hello, Alice! You are 25 years old.
Formatting strings with different data types
Python supports a variety of format specifiers for formatting different data types. For example, the %d format specifier is used to format integers, the %f format specifier is used to format floating-point numbers, and the %s format specifier is used to format strings.
Here is a table of some common format specifiers:
|
Format specifier |
Data type |
Example |
|---|---|---|
|
%d |
Integer |
10 |
|
%f |
Floating-point number |
3.14 |
|
%s |
String |
"Hello, world!" |
Formatting strings with alignment and precision
Python also allows you to specify the alignment and precision of formatted strings. For example, the : character can be used to specify the minimum field width of a formatted value. The . character can be used to specify the precision of a formatted floating-point number.
Example:
Python
# Format the string with a minimum field width of 10 and a precision of 2 decimal places
formatted_string = f"The value of pi is: {3.14159:10.2f}"
print(formatted_string)
Output:
The value of pi is: 3.14
Conclusion
Python string formatting is a powerful tool for formatting strings in Python. By understanding how to use string formatting, you can write more readable and maintainable code.