Python SciPy Constants – Multiple Examples

Welcome to this blog that will show you some of the constants in SciPy Python that are generally used.

Introduction

The Python SciPy module is a powerful tool for scientific computing. It provides a wide range of mathematical and physical constants, as well as other useful tools for working with numbers in Python.

Define SciPy constants package? 

The SciPy constants package is a sublibrary of SciPy. A range of mathematical and physical constants can be accessed by using the SciPy package. These constants are stored as variables within the package and can be accessed using the standard Python syntax for accessing variables.

To install the SciPy constants package, you can use:

import scipy.constants as const
Code language: Python (python)

List of Constants Available

There are several ways to access Python constants. You can use the module, library or package methods.

• scipy/constant_list.py – This file contains a list of all constants available in SciPy. It also includes some helper functions that can be used to print out these values or get them from their respective classes (e.g. float).

The following is a list of all available constants in SciPy:

Mathematical Constants

• pi: 3.1415926…..
• e: 2.718281…..
• inf/nan: Infinity or NaN (Not a Number)
• pow(): Exponentiation operator (x**y)
• golden ratio, Euler’s number, etc.

Physical Constants

Physical constants are numerical values that are used in physical sciences. The physical constants are mostly defined by international standards organizations such as the International Bureau of Weights and Measures (BIPM).

A few examples of physical constants include:

• The speed of light(c = 3.81*10**(8)),
• the gravitational constant(G = 1.67*10**(-11)),
• the Planck constant, and more

Constants commonly used in the python SciPy module include:

• Pi is a mathematical constant. It is the value of the ratio of the circumference of a circle and its diameter. It is approximately equal to 3.14159. To access it use this syntax:

import scipy.constants as const

pi = const.pi
print(pi)
Code language: Python (python)

Output

3.141592653589793
Code language: Python (python)

• The Gravitational Constant: It is denoted by G, is a physical constant that represents the strength of the gravitational force between two objects. It is approximately equal to 6.674 x 10^-11 m^3 kg^-1 s^-2. In the SciPy constants package, it can be accessed using the following syntax:

import scipy.constants as const

G = const.G
print(G)
Code language: Python (python)

Output

6.6743e-11
Code language: Python (python)

These constants are commonly used in the python SciPy module. You can find more information on their exact meanings here.

Categories for Units in Scipy Python

• Metric: Units of length, mass, and time using the metric system.
• Binary: It contains units of information using the binary system.
• Mass: It has all units of mass.
• Angle: This consists of units of angles.
• Time: This consists of units of time.
• Length: Units of length.
• Pressure: It is used in measuring the force exerted by air molecules on other objects.
• Volume: It can be measured with a scientific ruler or graduated cylinder.
• Speed: Units of speed
• Temperature: This is measured by using a thermometer or pyrometer.
• Energy; It has been defined as the amount of work done.
• Power: It’s easy to see how power can be calculated if you know how much energy was put into something (e.g., someone powering their laptop).

Metric

The metric system is a system of measurement that is based on the International System of Units (SI). It includes units of length (meters), mass (kilograms), and time (seconds). In the SciPy constants package, you can access these units using the following syntax:

import scipy.constants as const

length_unit = const.meter
mass_unit = const.kilogram
time_unit = const.second

print(f'Length unit: {length_unit}')
print(f'Mass unit: {mass_unit}')
print(f'Time unit: {time_unit}')
Code language: Python (python)

Output

Length unit: meter
Mass unit: kilogram
Time unit: second
Code language: Python (python)

Binary

The Binary constants are used to represent bits and binary numbers. These constants can be used in Python code as follows:

• To assign one or more bit strings to variables.
• To return a specific bit string from a function or method.

It includes units such as the bit (a unit of information equal to either 0 or 1) and the byte (a unit of information equal to 8 bits).

import scipy.constants as const

bit_unit = const.bit
byte_unit = const.byte

print(f'Bit unit: {bit_unit}')
print(f'Byte unit: {byte_unit}')
Code language: Python (python)

Output

Bit unit: bit
Byte unit: byte
Code language: Python (python)

Mass

Units of mass in the SciPy constants package include the gram (a unit of mass equal to one-thousandth of a kilogram) and the pound (a unit of mass equal to approximately 0.45 kilograms). Let me show you an example of this:

import scipy.constants as const

gram_unit = const.gram
pound_unit = const.pound

print(f'Gram unit: {gram_unit}')
print(f'Pound unit: {pound_unit}')
Code language: Python (python)

Output

Gram unit: gram
Pound unit: pound
Code language: Python (python)

Angle

An angle is a unit of measurement of the rotation of an object around a reference line. The angle can be thought of as being specified in radians or degrees, depending on how you want to think about it.

A basic definition tells us that if any two points are coplanar, then their angles add up to 180°.

import scipy.constants as const

degree_unit = const.degree
print(degree_unit)
Code language: Python (python)

Output

0.017453292519943295
Code language: Python (python)

Time

Time is a constant that defines the number of seconds since January 1, 1970.

You can use time constants to represent any point in time:

• A year (e.g. 2001)
• An hour (e.g. 3:00 pm) or hour and minute (3:00 PM)

import scipy.constants as const

second_unit = const.second
minute_unit = const.minute

print(f'Second unit: {second_unit}')
print(f'Minute unit: {minute_unit}')
Code language: Python (python)

Output

Second unit: second
Minute unit: minute
Code language: Python (python)

Length

The length() function in python returns the number of items in a list. It can be used to determine how many times each element appears in the list, or how many items there are altogether.

Although, Units of length in the SciPy constants package include the meter (the base unit of length in the International System of Units) and the inch (a unit of length equal to approximately 2.54 centimetres).

import scipy.constants as const

meter_unit = const.meter
inch_unit = const.inch

print(f'Meter unit: {meter_unit}')
print(f'Inch unit: {inch_unit}')
Code language: Python (python)

Output

Meter unit: meter
Inch unit: inch
Code language: Python (python)

Pressure

Pressure is a measure of the forces that act on an object. It is usually measured in pascals (Pa) or atmospheres (atm).

The units of pressure are Newtons per square meter, kilograms per square centimetre and pounds per square inch.

import scipy.constants as const

pascal_unit = const.pascal
atmosphere_unit = const.atmosphere

print(f'Pascal unit: {pascal_unit}')
print(f'Atmosphere unit: {atmosphere_unit}')
Code language: Python (python)

Output

Pascal unit: pascal
Atmosphere unit: atmosphere
Code language: Python (python)

Volume

Volume is a physical quantity that is the measure of the amount of space occupied by an object. Its units in the SciPy constants package include the litre (a unit of volume equal to one cubic decimeter) and the gallon (a unit of volume equal to approximately 3.785 litres).

import scipy.constants as const

litre_unit = const.litre
gallon_unit = const.gallon

print(f'Litre unit: {litre_unit}')
print(f'Gallon unit: {gallon_unit}')
Code language: Python (python)

Output

Litre unit: litre
Gallon unit: gallon
Code language: Python (python)

Speed

The speed of light in a vacuum is 299,792 km/s or 186,282 miles per second (or 2.9966×108 m/s). This is identical to its value on Earth and other planets that have an atmosphere like ours.

Its unit in the SciPy includes the meter per second (a unit of speed equal to the distance travelled in meters per second) and the mile per hour (a unit of speed equal to the distance travelled in miles per hour).

import scipy.constants as const

meter_per_hour_unit = const.mph
mile_per_hour_unit = const.mile/const.hour

print(f'Meter per hour unit: {meter_per_hour_unit}')
print(f'Mile per hour unit: {mile_per_hour_unit}')
Code language: Python (python)

Output

Meter per hour unit: 0.44703999999999994
Mile per hour unit: 0.44703999999999994
Code language: Python (python)

Temperature

Temperature is a physical quantity that quantifies the hotness or coldness of an object. It can be measured with a thermometer and its SI unit is degree Celsius (°C). The CGS unit for temperature is degrees Fahrenheit (°F).

import scipy.constants as const

kelvin_unit = const.kelvin
celsius_unit = const.degree_Celsius

print(f'Kelvin unit: {kelvin_unit}')
print(f'Celsius unit: {celsius_unit}')
Code language: Python (python)

Output

Kelvin unit: kelvin
Celsius unit: degree Celsius
Code language: Python (python)

Energy

The capacity or ability to do any work is Energy. It’s the ability to perform work. Energy is also the capability of performing work; if you have energy, then you can perform useful tasks like lifting weights, running upstairs and even doing calculus equations in your head!

Energy is measured in Joules (J). A joule is equal to one-newton meter squared per second squared (or 1 kg m2/s2).

import scipy.constants as const

joule_unit = const.joule
calorie_unit = const.calorie

print(f'Joule unit: {joule_unit}')
print(f'Calorie unit: {calorie_unit}')
Code language: Python (python)

Output

Joule unit: joule
Calorie unit: calorie
Code language: Python (python)

Power

Power is the rate of work done. It’s measured in watts (W) or kilowatts (kW). The units of power are watts, and joules per second. But, these can be confusing because they’re different from the SI unit of energy: kilojoules (kJ).

To calculate power, you multiply the voltage by current: V = I x W. Units of power in the SciPy constants package include the watt (the base unit of power in the International System of Units) and the horsepower (a unit of power equal to approximately 746 watts).

import scipy.constants as const

watt_unit = const.watt
horsepower_unit = const.horsepower

print(f'Watt unit: {watt_unit}')
print(f'Horsepower unit: {horsepower_unit}')
Code language: Python (python)

Output

Watt unit: watt
Horsepower unit: horsepower
Code language: Python (python)

Force 

Force is a vector quantity. It gives information about the rate of change of momentum.

Force can be applied to anybody, whether it’s an object or an electric current. For example, a gravitational force acts on objects that are attracted toward each other, while elastic forces act on objects when they are stretched or compressed (for example by being squeezed by another object). Magnetic forces also exist between magnets and metallic objects in which the magnetic field changes direction as you move through it; these types of forces are called electric currents.

import scipy.constants as const

newton_unit = const.newton
pound_force_unit = const.pound_force

print(f'Newton unit: {newton_unit}')
print(f'Pound-force unit: {pound_force_unit}')
Code language: Python (python)

Output

Newton unit: newton
Pound-force unit: pound-force
Code language: Python (python)

Conclusion

This article has covered some of the more common constants used in SciPy. The list of available constants is long and you can find many more by looking online or at your local library. If you have any questions about any of these or other Python SciPy-related topics, please let us know in the comments below!