SymPy http://www.sympy.org is a Python library for symbolic math.
In symbolic math, symbols are used to represent mathematical expressions. An example of a symbolic math expression is below.
The expression contains the symbols x, y, and z.
If we define a second symbolic math expression:
then we can substitue in a + b for x.
The result is the expression:
Solving for y in terms of a,b and z, results in:
In the symbolic math substitution above, symbolic math variables were rearranged, grouped and inserted. None of the variables were equal to a specific number, like 5 or 0.001, but you can still solve for one variable in terms on the other variables. If we have numerical values for z, a and b, we can use Python to calculate the value of y.
But if we don't have numerical values for z, a and b, Python and the SymPy package can be used to rearrange terms and solve for one variable in terms of the other.
Working with mathematical symbols in a programmatic way instead of working with numerical values in a programmatic way is called symbolic math. To work with symbolic math in Python, the SymPy library needs to be installed. SymPy comes pre-installed with the Anaconda distribution of Python. If you are not using the Anaconda distribution of Python, SymPy can be installed with the Anaconda Prompt. Use the command:
> conda install sympy