it's a click cli now, and PDF output is working as an option

app/config.py

@@ -1 +1 @@
-BEGIN_ANSWERS_TOKEN = "*BEGIN ANSWERS*"
+BEGIN_ANSWERS_TOKEN = "\n*BEGIN ANSWERS*\n"

app/main.py

@@ -1,19 +1,37 @@
 import sys
 
+import click
+from click import ClickException
+
 from app.generate import generate_answers, generate_problems
-from config import BEGIN_ANSWERS_TOKEN
+from app.config import BEGIN_ANSWERS_TOKEN
+from app.pdf import make_pdf
 
 
-def main():
-    if len(sys.argv) < 3:
-        print(
-            "please supply the number of bits and the number of exercises you'd like, "
-            "space-separated, like so:\n\n    $ binary 8 100\n"
+@click.command()
+@click.argument("bits", type=click.INT)
+@click.argument("num-problems", type=click.INT)
+@click.option("--pdf", default=False, is_flag=True)
+@click.option("--silent", default=False, is_flag=True)
+@click.option("--include-answers", default=True, is_flag=True)
+@click.option("--output-filepath")
+def main(
+    bits: int,
+    num_problems: int,
+    pdf: bool = False,
+    silent: bool = False,
+    include_answers: bool = True,
+    output_filepath: str = None,
+) -> None:
+
+    if pdf and silent:
+        raise ClickException(
+            "please specify either `pdf` or `silent`, not both (otherwise there "
+            "won't be any outcome of running the app!"
         )
-        sys.exit()
 
-    bits = int(sys.argv[1])
-    num_problems = int(sys.argv[2])
+    if pdf and output_filepath and not output_filepath.endswith("pdf"):
+        raise ClickException("Please include an output filepath ending in '.pdf'")
 
     problems = generate_problems(bits, num_problems)
     answers = generate_answers(problems)
@@ -23,5 +41,16 @@ def main():
         [f"{problem} | {answer} " for problem, answer in zip(problems, answers)]
     )
 
-    sys.stdout.write(BEGIN_ANSWERS_TOKEN.join((problems_string, answers_string)))
-    return problems_string, answers_string
+    if pdf:
+        make_pdf(
+            problems=problems_string,
+            answers=answers_string,
+            output_path=output_filepath or "problems.pdf",
+            include_answers=include_answers,
+        )
+
+    if not silent:
+        if include_answers:
+            click.echo(BEGIN_ANSWERS_TOKEN.join((problems_string, answers_string)))
+        else:
+            click.echo(problems_string)

app/pdf.py

@@ -0,0 +1,39 @@
+import os
+import subprocess
+import tempfile
+
+
+def make_pdf(
+    problems: str, answers: str, output_path: str, include_answers: bool
+) -> None:
+    if include_answers:
+        pdf_jobs = (("problems", problems), ("answers", answers))
+    else:
+        pdf_jobs = ("problems", problems)
+
+    for job_name, job in pdf_jobs:
+
+        if job_name == "answers":
+            path, filename = os.path.split(output_path)
+            new_filename = f"{filename.split('.pdf')[0]}-answers.pdf"
+            output_path = os.path.join(path, new_filename)
+
+        with tempfile.NamedTemporaryFile(mode="w") as txt_file:
+            txt_file.write(job)
+            txt_file.flush()
+
+            command = (
+                f"enscript --columns=4 --no-header --output=tempfile.ps {txt_file.name}"
+            )
+            print(f"command: '{command}'")
+
+            output = subprocess.check_output(command, shell=True)
+            print(output)
+
+            command = f"ps2pdf tempfile.ps {output_path}"
+            print(f"command: '{command}'")
+
+            output = subprocess.check_output(command, shell=True)
+            print(output)
+        print("made pdf", output_path)
+        os.unlink("tempfile.ps")

app/test/test_generate.py

@@ -1,4 +1,3 @@
-
 from app.generate import generate, generate_problems
 from app.check import check
 
@@ -6,9 +5,9 @@ from app.check import check
 def test_generate():
     first_problem = generate(bits=5)
     assert len(first_problem) == 5
-    assert all(char in ('1', '0') for char in first_problem)
-    assert '1' in first_problem
-    assert '0' in first_problem
+    assert all(char in ("1", "0") for char in first_problem)
+    assert "1" in first_problem
+    assert "0" in first_problem
 
 
 def test_generate_problems():
@@ -16,14 +15,12 @@ def test_generate_problems():
     first_problem = problems[0]
     assert len(problems) == 100
     assert len(first_problem) == 5
-    assert all(char in ('1', '0') for char in first_problem)
-    assert '1' in first_problem
-    assert '0' in first_problem
+    assert all(char in ("1", "0") for char in first_problem)
 
 
 def test_check():
-    assert check('110') == 6
-    assert check('000') == 0
-    assert check('001') == 1
-    assert check('011') == 3
-    assert check('010') == 2
+    assert check("110") == 6
+    assert check("000") == 0
+    assert check("001") == 1
+    assert check("011") == 3
+    assert check("010") == 2