extract_code.py

#!/usr/bin/env python

import os
import re
import subprocess

def doctest_2to3_results(src_iterator):
 """transforms the results sections of a doctests source to fit with python3"""
 for line in src_iterator:
 if line.startswith(">>>") or line.startswith("..."):
 yield line
 else:
 # TODO: um, this happens to work for the tutorial, but isn't the most robust...
 if "u'" in line:
 line = line.replace("u'", "'")
 if 'u"' in line:
 line = line.replace('u"', '"')
 yield line

def extract_code(src_iterator):
 """extracts the code from a doctests source"""
 for line in src_iterator:
 line = line.replace("echo=False", "echo=True")
 if "doctest:" in line and "#" in line:
 comment_start = line.rfind("#", 0, line.rfind("doctest:"))
 if comment_start != -1:
 line = line[:comment_start].rstrip()
 if line.startswith(">>>") or line.startswith("..."):
 line = line[4:]
 if not line:
 yield " \n"
 have_break = False
 else:
 yield line.rstrip()+"\n"
 have_break = not line.strip()
 elif line.startswith("#"):
 yield line.rstrip()+"\n"
 have_break = False
 elif not line.strip() and not have_break:
 yield "\n"
 have_break = True

subprocess.call(["2to3", "-d", "-w", "-n", "--add-suffix=3", "-o", ".", "steps2.txt"])

with open("steps3.txt", "w") as fix_file, open("steps2.txt3", "r") as src_file:
 for line in doctest_2to3_results(src_file):
 fix_file.write(line)

os.remove("steps2.txt3")

with open("blogapp2.py", "w") as py_file, open("steps2.txt") as steps_file:
 py_file.write("#!/usr/bin/env python\n\n")
 have_break = True
 for line in extract_code(steps_file):
 py_file.write(line)

with open("blogapp3.py", "w") as py_file, open("steps3.txt") as steps_file:
 py_file.write("#!/usr/bin/env python\n\n")
 have_break = True
 for line in extract_code(steps_file):
 py_file.write(line)