# SciPy Constants

## Constants in SciPy

As SciPy is more focused on scientific implementations, it provides many built-in scientific constants.

These constants can be helpful when you are working with Data Science.

PI is an example of a scientific constant.

### Example

Print the constant value of PI:

Try it Yourself »

## Constant Units

A list of all units under the constants module can be seen using the `dir()` function.

### Example

List all constants:

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## Unit Categories

The units are placed under these categories:

• Metric
• Binary
• Mass
• Angle
• Time
• Length
• Pressure
• Volume
• Speed
• Temperature
• Energy
• Power
• Force

## Metric (SI) Prefixes:

Return the specified unit in meter (e.g. `centi` returns `0.01`)

### Example

Try it Yourself »

## Binary Prefixes:

Return the specified unit in bytes (e.g. `kibi` returns `1024`)

### Example

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## Mass:

Return the specified unit in kg (e.g. `gram` returns `0.001`)

### Example

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## Angle:

Return the specified unit in radians (e.g. `degree` returns `0.017453292519943295`)

### Example

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## Time:

Return the specified unit in seconds (e.g. `hour` returns `3600.0`)

### Example

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## Length:

Return the specified unit in meters (e.g. `nautical_mile` returns `1852.0`)

### Example

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## Pressure:

Return the specified unit in pascals (e.g. `psi` returns `6894.757293168361`)

### Example

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## Area:

Return the specified unit in square meters(e.g. `hectare` returns `10000.0`)

### Example

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## Volume:

Return the specified unit in cubic meters (e.g. `liter` returns `0.001`)

### Example

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## Speed:

Return the specified unit in meters per second (e.g. `speed_of_sound` returns `340.5`)

### Example

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## Temperature:

Return the specified unit in Kelvin (e.g. `zero_Celsius` returns `273.15`)

### Example

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## Energy:

Return the specified unit in joules (e.g. `calorie` returns `4.184`)

### Example

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## Power:

Return the specified unit in watts (e.g. `horsepower` returns `745.6998715822701`)

### Example

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## Force:

Return the specified unit in newton (e.g. `kilogram_force` returns `9.80665`)

### Example

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## Exercise:

Insert the correct syntax for printing the kilometer unit (in meters):

Start the Exercise