Scientific Notation in Python

1. Use the format() Function to Represent Values in Scientific Notation in Python
2. Use the fstrings to Represent Values in Scientific Notation in Python
3. Use the numpy.format_float_scientific() Function to Represent Values in Scientific Notation

Scientific notation is used for representing very large or small numbers in a compact and understandable way. Such notation is also used in programming; for example, 6000000 can be represented as 6E+6. Similarly, 0.000006 can be represented as 6E-6.

In this tutorial, we will discuss how to use such scientific notations in Python.

Use the format() Function to Represent Values in Scientific Notation in Python

The format function is used for formatting strings in a specific format. We can use this function to convert large or small float values to their respective exponential format as shown below:

no1 = float(5800000.00000)
no2 = float(0.0000058)
print(format(no1, ".1E"))
print(format(no2, ".1E"))

Output:

5.8E+06
5.8E-06

Here .1E is the specified formatting pattern. E indicates exponential notation to print the value in scientific notation, and .1 specifies that there has to be one digit after the decimal.

Use the fstrings to Represent Values in Scientific Notation in Python

In Python 3.6 and up, we can use fstrings to format strings. This method is considered to be more precise and less prone to errors. It improves the readability of the code compared to the traditional format() function. fstrings can help in representing, as shown below.

no1 = float(5800000.00000)
no2 = float(0.0000058)
print(f"{no1:.1E}")
print(f"{no2:.1E}")

Output:

5.8E+06
5.8E-06

Notice that the format pattern is the same as the above method.

Use the numpy.format_float_scientific() Function to Represent Values in Scientific Notation

The NumPy module in Python has a function format_float_scientific() that can be used to format a floating value to its scientific notation.

We can use the precision parameter to specify the total decimal digits and the exp_digits to tell how many digits are needed in the exponential notation. Other parameters available are sign, unique, and trim, which offer more customizations.

The final result returned from this function is a string.

import numpy as np

no1 = float(5800000.00000)
no2 = float(0.0000058)

print(np.format_float_scientific(no1, precision=1, exp_digits=3))
print(np.format_float_scientific(no2, precision=2, exp_digits=3))

Output:

5.8e+006
5.8e-006