"""Adds a directory to sys.path, permanently. """ import sys import os import site HEADER = """\ # .pth file created by the pypath script. # edit at your own risk """ SITEDIR = site.getusersitepackages() PATH = os.path.join(SITEDIR, "pypath.pth") if not os.path.exists(SITEDIR): os.mkdirs(SITEDIR) def add(path, pth_file=None): path = path.strip() pth_file = pth_file or PATH if not os.path.exists(path): raise ValueError("doesn't exist: {}".format(path)) with open(pth_file, "r") as f: for line in f: if line.strip(os.linesep) == path: # already added return empty = not f.tell() with open(pth_file, "a") as f: if empty: f.write(HEADER) f.write(os.linesep + path) def remove(path, pth_file=None): pth_file = pth_file or PATH try: with open(pth_file, "r") as f: lines = f.read().splitlines()[2:] except IOError: raise ValueError("not found: {}".format(path)) try: lines.remove(path) except ValueError: raise ValueError("not found: {}".format(path)) lines.insert(0, HEADER) with open(pth_file, "w") as f: f.write(os.linesep.join(lines)) def show(pth_file=None): pth_file = pth_file or PATH print("current paths ({}):".format(pth_file)) try: f = open(pth_file, "r") except IOError: return with f: lines = f.read() if not lines.startswith(HEADER): raise ValueError(".pth file is invalid: {}".format(pth_file)) for line in lines.splitlines()[2:]: if not line.strip(): continue print(line) if __name__ == "__main__": import argparse EPILOG = "If no args are passed, the current contents are shown." parser = argparse.ArgumentParser(epilog=EPILOG) group = parser.add_mutually_exclusive_group() group.add_argument("-a", "--add", metavar="PATH") group.add_argument("-r", "--remove", metavar="PATH") parser.add_argument("-f", "--file", metavar="") args = parser.parse_args() if args.add: add(args.add, args.file) elif args.remove: remove(args.remove, args.file) else: show(args.file)