al8 / examgen

A Python class that can automatically generate mathematics exams, with solution keys, using Sympy and LaTeX.

Math exam generator

A Python class that can automatically generate mathematics worksheets/exams, with solution keys, using Sympy and LaTeX. Meant for instructors, tutors, and student study groups, etc.

Requirements

• Python 2.7 (Python 3 support coming soon)
• Sympy
• LaTeX

Quickstart Example

from examgen import exam

# make an exam with a filename and title
myexam = exam("algebra1", "Algebra 101 exam 1")

# add some problem sections
# syntax: problem type, # of problems, section title, instructions
myexam.add_section("Linear equations", 20, "Linear equations",
                   "Solve the following equations for the specified variable.")
myexam.add_section("Quadratic equations", 20, "Quadratic equations",
                   "Solve the following quadratic equations.")

# generate the exam and solutions pdf
myexam.write()

Running this code will generate algebra1.pdf and algebra1_solutions.pdf. The LaTeX .tex, .log and .aux files will automatically be deleted after compiling. If you would rather save the .tex files for further modifications, pass the savetex flag when making your exam:

myexam = exam("algebra1", "Algebra 101 exam 1", savetex=True)

The two problem types used above ("Linear equations" and "Quadratic equations") are aliases to linear and quadratic problem generators defined in examgen/lib/algebra.py (make_linear_eq and make_quadratic_eq, respectively).

The are functions which may or may not require any arguments, but always return a tuple of two LaTeX-compatible strings each time they are called. The first string is the problem generated, the second is the corresponding solution.

For example, this is the quadratic equation generator/solver:

def make_quadratic_eq(x="x", rhs = None):
    """
    Generates quadratic equation problem expression and
    set of solutions

    x : character for the variable to be solved for. defaults to "x".
                            OR
        a list of possible characters. A random selection will be made from them.
    
    rhs : value to set for the right-hand side. If not given, the 
          right-hand side will be a randomly generated polynomial expression
          of degree <= 2, in the same variable.
    """
    if isinstance(x, str):
        x = sympy.Symbol(x)
    elif isinstance(x, list):
        x = sympy.Symbol(random.choice(x))
    c1, c2, c3 = get_coefficients(3)
    lhs = c1*x**2 + c2*x + c3

    if rhs == None:
        c4, c5, c6 = get_coefficients(3, first_nonzero=False)
        rhs = c4*x**2 + c5*x + c6
    
    e = sympy.Eq(lhs, rhs)
    sols = [render(ex, x) for ex in sympy.solve(e, x)]
    if len(sols) == 0:
        return make_quadratic_eq()
    return render(e), sols

The get_coefficients(n) function is just a helper function for generating random coefficients, and render(string) is a function that places $$ charectors properly for LaTeX rendering.

Extending for new problem types

The exam.add_section() method will actually accept any function that returns two strings as a problem generator, in addition to a built-in text alias. This method will also accept arguments to be passed to problem generating functions. This way, the code can be easily extended to new subject areas.

So for example, if you define a custom generating function my_problem(arg1, arg2=val) with required argument arg1 and keyword argument arg2, you can add a section of 15 problems of this type to your exam by calling:

myexam..add_section(my_problem, 15, "Cool problems",
                 "Solve these problems", arg1_val, arg2=arg2_val)

You can use this to refine existing problem generating functions to meet your needs. For example, if you would like to generate a 10 problem section of quadratic equations that are in the variables x, y, or z, we see that the function make_quadratic_eq() shown above will accept a list for its argument x. So we can call:

myexam.add_section(make_quadratic_eq, 20, "Quadratic equations",
                   "Solve the following quadratic equations.", ["x", "y", "z"])

and this will randomly generate the quadratic equation section with problems in the variables x, y, and z.

Goals

Over time, I plan on extending built-in support for problem types from elementary algebra and trigonometry through calculus, differential equations, and linear algebra (and likely beyond). I'm also planning on extending support for generating exams from static sets of problems (rather than purely generated ones). This could be very helpful for graduate level material or qualifier exam prep.

A no-installation GUI application (build using pyinstaller) would also be helpful for educators who don't have much experience in Python or CLI.