Added physical pressure units (#5613)

* Added physical pressure units

This uses tuple pair which stores units required to be converted to respective other units as mentioned.
Available Units:- Pascal,Bar,Kilopascal,Megapascal,psi(pound per square inch),inHg(in mercury column),torr,atm

* Formatted file

File was formatted as per repo rules

* Reformatted file :)

* Added more reference

* More reference added

conversions/pressure_conversions.py

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+"""
+Conversion of pressure units.
+Available Units:- Pascal,Bar,Kilopascal,Megapascal,psi(pound per square inch),
+inHg(in mercury column),torr,atm
+USAGE :
+-> Import this file into their respective project.
+-> Use the function pressure_conversion() for conversion of pressure units.
+-> Parameters :
+    -> value : The number of from units you want to convert
+    -> from_type : From which type you want to convert
+    -> to_type : To which type you want to convert
+REFERENCES :
+-> Wikipedia reference: https://en.wikipedia.org/wiki/Pascal_(unit)
+-> Wikipedia reference: https://en.wikipedia.org/wiki/Pound_per_square_inch
+-> Wikipedia reference: https://en.wikipedia.org/wiki/Inch_of_mercury
+-> Wikipedia reference: https://en.wikipedia.org/wiki/Torr
+-> https://en.wikipedia.org/wiki/Standard_atmosphere_(unit)
+-> https://msestudent.com/what-are-the-units-of-pressure/
+-> https://www.unitconverters.net/pressure-converter.html
+"""
+
+from collections import namedtuple
+
+from_to = namedtuple("from_to", "from_ to")
+
+PRESSURE_CONVERSION = {
+    "atm": from_to(1, 1),
+    "pascal": from_to(0.0000098, 101325),
+    "bar": from_to(0.986923, 1.01325),
+    "kilopascal": from_to(0.00986923, 101.325),
+    "megapascal": from_to(9.86923, 0.101325),
+    "psi": from_to(0.068046, 14.6959),
+    "inHg": from_to(0.0334211, 29.9213),
+    "torr": from_to(0.00131579, 760),
+}
+
+
+def pressure_conversion(value: float, from_type: str, to_type: str) -> float:
+    """
+    Conversion between pressure units.
+    >>> pressure_conversion(4, "atm", "pascal")
+    405300
+    >>> pressure_conversion(1, "pascal", "psi")
+    0.00014401981999999998
+    >>> pressure_conversion(1, "bar", "atm")
+    0.986923
+    >>> pressure_conversion(3, "kilopascal", "bar")
+    0.029999991892499998
+    >>> pressure_conversion(2, "megapascal", "psi")
+    290.074434314
+    >>> pressure_conversion(4, "psi", "torr")
+    206.85984
+    >>> pressure_conversion(1, "inHg", "atm")
+    0.0334211
+    >>> pressure_conversion(1, "torr", "psi")
+    0.019336718261000002
+    >>> pressure_conversion(4, "wrongUnit", "atm")
+    Traceback (most recent call last):
+      File "/usr/lib/python3.8/doctest.py", line 1336, in __run
+        exec(compile(example.source, filename, "single",
+      File "<doctest __main__.pressure_conversion[8]>", line 1, in <module>
+        pressure_conversion(4, "wrongUnit", "atm")
+      File "<string>", line 67, in pressure_conversion
+    ValueError: Invalid 'from_type' value: 'wrongUnit'  Supported values are:
+    atm, pascal, bar, kilopascal, megapascal, psi, inHg, torr
+    """
+    if from_type not in PRESSURE_CONVERSION:
+        raise ValueError(
+            f"Invalid 'from_type' value: {from_type!r}  Supported values are:\n"
+            + ", ".join(PRESSURE_CONVERSION)
+        )
+    if to_type not in PRESSURE_CONVERSION:
+        raise ValueError(
+            f"Invalid 'to_type' value: {to_type!r}.  Supported values are:\n"
+            + ", ".join(PRESSURE_CONVERSION)
+        )
+    return (
+        value * PRESSURE_CONVERSION[from_type].from_ * PRESSURE_CONVERSION[to_type].to
+    )
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()