The basic construction element to build a formula in SymPy is the symbol. As we saw in the introductory example, a symbol is created by the command symbols. This SymPy command generates symbol objects from a given string:
x, y, mass, torque = symbols('x y mass torque')
It is actually a short form of the following command:
symbol_list=[symbols(l) for l in 'x y mass torque'.split()]
Followed by an unpacking step to obtain variables:
x, y, mass, torque = symbol_list
The arguments of the command define the string representation of the symbol. The variable name of the symbol chosen is often identical to its string representation, but this is not required by the language:
row_index=symbols('i',integer=True)
print(row_index**2) # returns i**2
Here, we also defined that the symbol is assumed to be an integer.
An entire set of symbols can be defined in a very compact way:
integervariables = symbols...
