"""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="<path to .pth file>")
args = parser.parse_args()
if args.add:
add(args.add, args.file)
elif args.remove:
remove(args.remove, args.file)
else:
show(args.file)
