Mercurial > python-hglib
view hglib/util.py @ 148:c1b966866ed7
hglib: make all imports absolute (issue4520)
author | Brett Cannon <brett@python.org> |
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date | Fri, 13 Mar 2015 14:46:13 -0400 |
parents | 8d7bf729a4db |
children | 958307b30af3 |
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import itertools, os, subprocess, sys from hglib import error try: from io import BytesIO except ImportError: from cStringIO import StringIO as BytesIO if sys.version_info[0] > 2: def b(s): """Encode the string as bytes.""" return s.encode('latin-1') else: def b(s): """Encode the string as bytes.""" return s def grouper(n, iterable): ''' list(grouper(2, range(4))) -> [(0, 1), (2, 3)] ''' args = [iter(iterable)] * n return itertools.izip(*args) def eatlines(s, n): """ >>> eatlines("1\\n2", 1) '2' >>> eatlines("1\\n2", 2) '' >>> eatlines("1\\n2", 3) '' >>> eatlines("1\\n2\\n3", 1) '2\\n3' """ cs = BytesIO(s) for line in cs: n -= 1 if n == 0: return cs.read() return b('') def skiplines(s, prefix): """ Skip lines starting with prefix in s >>> skiplines('a\\nb\\na\\n', 'a') 'b\\na\\n' >>> skiplines('a\\na\\n', 'a') '' >>> skiplines('', 'a') '' >>> skiplines('a\\nb', 'b') 'a\\nb' """ cs = BytesIO(s) for line in cs: if not line.startswith(prefix): return line + cs.read() return b('') def cmdbuilder(name, *args, **kwargs): """ A helper for building the command arguments args are the positional arguments kwargs are the options keys that are single lettered are prepended with '-', others with '--', underscores are replaced with dashes keys with False boolean values are ignored, lists add the key multiple times None arguments are skipped >>> cmdbuilder('cmd', a=True, b=False, c=None) ['cmd', '-a'] >>> cmdbuilder('cmd', long=True) ['cmd', '--long'] >>> cmdbuilder('cmd', str='s') ['cmd', '--str', 's'] >>> cmdbuilder('cmd', d_ash=True) ['cmd', '--d-ash'] >>> cmdbuilder('cmd', _=True) ['cmd', '-'] >>> cmdbuilder('cmd', list=[1, 2]) ['cmd', '--list', '1', '--list', '2'] >>> cmdbuilder('cmd', None) ['cmd'] """ cmd = [name] for arg, val in kwargs.items(): if val is None: continue arg = arg.replace(b('_'), b('-')) if arg != b('-'): if len(arg) == 1: arg = b('-') + arg else: arg = b('--') + arg if isinstance(val, bool): if val: cmd.append(arg) elif isinstance(val, list): for v in val: cmd.append(arg) cmd.append(str(v)) else: cmd.append(arg) cmd.append(str(val)) for a in args: if a is not None: cmd.append(a) return cmd class reterrorhandler(object): """This class is meant to be used with rawcommand() error handler argument. It remembers the return value the command returned if it's one of allowed values, which is only 1 if none are given. Otherwise it raises a CommandError. >>> e = reterrorhandler('') >>> bool(e) True >>> e(1, 'a', '') 'a' >>> bool(e) False """ def __init__(self, args, allowed=None): self.args = args self.ret = 0 if allowed is None: self.allowed = [1] else: self.allowed = allowed def __call__(self, ret, out, err): self.ret = ret if ret not in self.allowed: raise error.CommandError(self.args, ret, out, err) return out def __nonzero__(self): """ Returns True if the return code was 0, False otherwise """ return self.ret == 0 class propertycache(object): """ Decorator that remembers the return value of a function call. >>> class obj(object): ... def func(self): ... print 'func' ... return [] ... func = propertycache(func) >>> o = obj() >>> o.func func [] >>> o.func [] """ def __init__(self, func): self.func = func self.name = func.__name__ def __get__(self, obj, type=None): result = self.func(obj) setattr(obj, self.name, result) return result close_fds = os.name == 'posix' startupinfo = None if os.name == 'nt': startupinfo = subprocess.STARTUPINFO() startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW def popen(args, env={}): environ = None if env: environ = dict(os.environ) environ.update(env) return subprocess.Popen(args, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, close_fds=close_fds, startupinfo=startupinfo, env=environ)