What does 0.2 F mean in Python?

Question

“print” treats the % as a special character you need to add, so it can know, that when you type “f”, the number (result) that will be printed will be a floating point type, and the “.2” tells your “print” to print only the first 2 digits after the point.

Table of Contents Show

What is 4 divided by 3?
Understanding the structure of 0.3f
Understanding width and precision in Python
Stage 1 - Using only 1.333 1.333 1.3331 representation
Stage 2 - Adding width
Stage 3 - Adding precision
Using width and precision with integers
Formatting integers with the Width
Formatting integers with precision
Using width and precision with strings
Formatting string with Width
How to align your strings left and right?
Formatting string with precision
How do I format .2f in Python?
What does .0f mean in Python?
What does 0.3 F mean in Python?
What does .2f mean in Python?

If you have learned C, C++, or Bash, you would be familiar with the

1.333333
1.333333
1.333333

7 function. It is used for printing formatted data to stdout.

Question - Does Python have something similar to

1.333333
1.333333
1.333333

8?

Answer - Not really. Python only provides the

1.333333
1.333333
1.333333

9 function.

However, you can mimic the behavior of

# Using % operator
print("%0.3f"%(4/3))

# Using format method
print("{:0.3f}".format(4/3))

# Using f-strings
print(f"{4/3:0.3f}")

0 by using string formatting.

This is where terms like width and precision come into play.

In this article, you will learn the intricacies of using width and precision with string formatting by comparing 3 different ways of string formatting.

What is 4 divided by 3?

Let’s print the floating-point representation of

# Using % operator
print("%0.3f"%(4/3))

# Using format method
print("{:0.3f}".format(4/3))

# Using f-strings
print(f"{4/3:0.3f}")

1.

Code

# Using % operator
print("%f"%(4/3))

# Using format method
print("{:f}".format(4/3))

# Using f-strings
print(f"{4/3:f}")

Output

1.333333
1.333333
1.333333

Each of the above formatting methods, produces the same output. The output of

# Using % operator
print("%0.3f"%(4/3))

# Using format method
print("{:0.3f}".format(4/3))

# Using f-strings
print(f"{4/3:0.3f}")

1 has 6 digits after the decimal.

Let’s try to limit the number of decimal places to 3.

Code

# Using % operator
print("%0.3f"%(4/3))

# Using format method
print("{:0.3f}".format(4/3))

# Using f-strings
print(f"{4/3:0.3f}")

Output

1.333
1.333
1.333

By using

# Using % operator
print("%0.3f"%(4/3))

# Using format method
print("{:0.3f}".format(4/3))

# Using f-strings
print(f"{4/3:0.3f}")

3 as format placeholders, we are able to contain the number of decimal places to 3.

Understanding the structure of 0.3f

Let’s generalize

# Using % operator
print("%0.3f"%(4/3))

# Using format method
print("{:0.3f}".format(4/3))

# Using f-strings
print(f"{4/3:0.3f}")

3 into a formula -

# Using % operator
print("%0.3f"%(4/3))

# Using format method
print("{:0.3f}".format(4/3))

# Using f-strings
print(f"{4/3:0.3f}")

5

# Using % operator
print("%0.3f"%(4/3))

# Using format method
print("{:0.3f}".format(4/3))

# Using f-strings
print(f"{4/3:0.3f}")

6 represents the minimum width or padding of the output string.

# Using % operator
print("%0.3f"%(4/3))

# Using format method
print("{:0.3f}".format(4/3))

# Using f-strings
print(f"{4/3:0.3f}")

7 represents the maximum number of characters after the decimal.

# Using % operator
print("%0.3f"%(4/3))

# Using format method
print("{:0.3f}".format(4/3))

# Using f-strings
print(f"{4/3:0.3f}")

8 symbolizes floating-point representation.

Let’s alter the

# Using % operator
print("%0.3f"%(4/3))

# Using format method
print("{:0.3f}".format(4/3))

# Using f-strings
print(f"{4/3:0.3f}")

6 and

# Using % operator
print("%0.3f"%(4/3))

# Using format method
print("{:0.3f}".format(4/3))

# Using f-strings
print(f"{4/3:0.3f}")

7 values and see how the output changes.

Code

# Using % operator
print("%10.2f"%(4/3))

# Using format method
print("{:10.2f}".format(4/3))

# Using f-strings
print(f"{4/3:10.2f}")

Output

      1.33
      1.33
      1.33

You can see that your result contains empty white spaces to the left of each output.

So what happened? Let’s dive in.

Understanding width and precision in Python

Stage 1 - Using only 1.333 1.333 1.3331 representation

If you just use

1.333
1.333
1.333

1 representation, the output will have a width/length of 8.

Code

# Using % operator
print("%f"%(4/3))

# Using format method
print("{:f}".format(4/3))

# Using f-strings
print(f"{4/3:f}")

Output

1.333333
1.333333
1.333333

Formatting width and precision in Python strings

Stage 2 - Adding width

Let’s add only a

1.333
1.333
1.333

3 placeholder to

1.333
1.333
1.333

1.

Code

# Using % operator
print("%10f"%(4/3))

# Using format method
print("{:10f}".format(4/3))

# Using f-strings
print(f"{4/3:10f}")

When the user-defined width is different(greater or smaller) than the original width, the length of the output is changed to the user-defined width. In the above example, the new length of output will be 10 characters long.

Output

# Using % operator
print("%f"%(4/3))

# Using format method
print("{:f}".format(4/3))

# Using f-strings
print(f"{4/3:f}")

0

The resulting output is now right-aligned with extra 2 white space characters added as padding to the left.

Adding extra width to string formating in Python

However, if the user-defined width is 0, the original length of the output is maintained.

Try providing the

1.333
1.333
1.333

3 as 0.

1.333
1.333
1.333

6 will provide the same result as using

# Using % operator
print("%0.3f"%(4/3))

# Using format method
print("{:0.3f}".format(4/3))

# Using f-strings
print(f"{4/3:0.3f}")

8 floating-point representation.

Code

# Using % operator
print("%f"%(4/3))

# Using format method
print("{:f}".format(4/3))

# Using f-strings
print(f"{4/3:f}")

1

Output

1.333333
1.333333
1.333333

Stage 3 - Adding precision

Let’s now change the number of decimal places in the output to 2. This can be done by providing the

1.333
1.333
1.333

8 value.

Code

# Using % operator
print("%10.2f"%(4/3))

# Using format method
print("{:10.2f}".format(4/3))

# Using f-strings
print(f"{4/3:10.2f}")

Upon fixing the

1.333
1.333
1.333

8 to 2, the resulting output will only have 2 characters after the decimal. All the other characters after the 2nd decimal places are chopped off.

Hence, the output string moves even further to the right, creating more empty white spaces.

Output

      1.33
      1.33
      1.33

Fix the precision of string formatting in Python

Using width and precision with integers

Formatting integers with the Width

Formatting integers with width has a similar effect as formatting floating points.

Code

# Using % operator
print("%f"%(4/3))

# Using format method
print("{:f}".format(4/3))

# Using f-strings
print(f"{4/3:f}")

5

Output

# Using % operator
print("%f"%(4/3))

# Using format method
print("{:f}".format(4/3))

# Using f-strings
print(f"{4/3:f}")

6

Adding width to integer formatting in Python

Formatting integers with precision

However, providing precision with

# Using % operator
print("%10.2f"%(4/3))

# Using format method
print("{:10.2f}".format(4/3))

# Using f-strings
print(f"{4/3:10.2f}")

0 formatting has no effect and with

# Using % operator
print("%10.2f"%(4/3))

# Using format method
print("{:10.2f}".format(4/3))

# Using f-strings
print(f"{4/3:10.2f}")

1 and

# Using % operator
print("%10.2f"%(4/3))

# Using format method
print("{:10.2f}".format(4/3))

# Using f-strings
print(f"{4/3:10.2f}")

2 method, it throws an error.

Code/Output - precision with % operator

# Using % operator
print("%f"%(4/3))

# Using format method
print("{:f}".format(4/3))

# Using f-strings
print(f"{4/3:f}")

7

Code/Output - precision with format and f-strings

# Using % operator
print("%f"%(4/3))

# Using format method
print("{:f}".format(4/3))

# Using f-strings
print(f"{4/3:f}")

8

Using width and precision with strings

Formatting string with Width

Unfortunately, the default alignment differs between

# Using % operator
print("%10.2f"%(4/3))

# Using format method
print("{:10.2f}".format(4/3))

# Using f-strings
print(f"{4/3:10.2f}")

0 formatting (old style) and formatting with

# Using % operator
print("%10.2f"%(4/3))

# Using format method
print("{:10.2f}".format(4/3))

# Using f-strings
print(f"{4/3:10.2f}")

2 method and

# Using % operator
print("%10.2f"%(4/3))

# Using format method
print("{:10.2f}".format(4/3))

# Using f-strings
print(f"{4/3:10.2f}")

1 (new style).

The old-style defaults to right-aligned while for new style it’s left.

Code

# Using % operator
print("%f"%(4/3))

# Using format method
print("{:f}".format(4/3))

# Using f-strings
print(f"{4/3:f}")

9

Output

1.333333
1.333333
1.333333

0

String formatting with width in Python

You can change this behavior easily by using certain operators.

How to align your strings left and right?

To right-align your string, use

# Using % operator
print("%10.2f"%(4/3))

# Using format method
print("{:10.2f}".format(4/3))

# Using f-strings
print(f"{4/3:10.2f}")

6 operator with the new formatting methods.

Code - To right align strings

1.333333
1.333333
1.333333

1

Output

1.333333
1.333333
1.333333

2

To left-align your string, use

# Using % operator
print("%10.2f"%(4/3))

# Using format method
print("{:10.2f}".format(4/3))

# Using f-strings
print(f"{4/3:10.2f}")

7 operator with the old formatting method.

Code - To left-align strings

1.333333
1.333333
1.333333

3

Output

1.333333
1.333333
1.333333

4

Formatting string with precision

When you add

1.333
1.333
1.333

8 to string formatting, the characters of the string are truncated.

Let’s say, you provide a precision of

# Using % operator
print("%10.2f"%(4/3))

# Using format method
print("{:10.2f}".format(4/3))

# Using f-strings
print(f"{4/3:10.2f}")

9. All the characters except the first

# Using % operator
print("%10.2f"%(4/3))

# Using format method
print("{:10.2f}".format(4/3))

# Using f-strings
print(f"{4/3:10.2f}")

9 characters are truncated.

How do I format .2f in Python?

2f are called as format specifiers, they begin with % followed by character that represents the data type. For e.g %d format specifier is a placeholder for a integer, similarly %. 2f is a placeholder for floating point number. ... Python String Formatting..

What does .0f mean in Python?

Format Specifier This defines how individual values are presented. Here, we'll use the syntax index colon specifier. One of the most common format specifiers is float represented by f . In the code, we specify that the value passed with the index 0 will be a float.

What does 0.3 F mean in Python?

%.3f. f : Floating point, which means that the value that is going to be printed is a real number. . 3 is for the number of decimals after the point. That means that the real value to be printed will have 3 digits after the point.

What does .2f mean in Python?

A format of . 2f (note the f ) means to display the number with two digits after the decimal point. So the number 1 would display as 1.00 and the number 1.5555 would display as 1.56 .