Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/past/builtins/noniterators.py: 38%

1"""

2This module is designed to be used as follows::

4 from past.builtins.noniterators import filter, map, range, reduce, zip

6And then, for example::

8 assert isinstance(range(5), list)

10The list-producing functions this brings in are::

12- ``filter``

13- ``map``

14- ``range``

15- ``reduce``

16- ``zip``

18"""

20from __future__ import division, absolute_import, print_function

22from itertools import chain, starmap

23import itertools # since zip_longest doesn't exist on Py2

24from past.types import basestring

25from past.utils import PY3

28def flatmap(f, items):

29 return chain.from_iterable(map(f, items))

32if PY3:

33 import builtins

35 # list-producing versions of the major Python iterating functions

36 def oldfilter(*args):

37 """

38 filter(function or None, sequence) -> list, tuple, or string

40 Return those items of sequence for which function(item) is true.

41 If function is None, return the items that are true. If sequence

42 is a tuple or string, return the same type, else return a list.

43 """

44 mytype = type(args[1])

45 if isinstance(args[1], basestring):

46 return mytype().join(builtins.filter(*args))

47 elif isinstance(args[1], (tuple, list)):

48 return mytype(builtins.filter(*args))

49 else:

50 # Fall back to list. Is this the right thing to do?

51 return list(builtins.filter(*args))

53 # This is surprisingly difficult to get right. For example, the

54 # solutions here fail with the test cases in the docstring below:

55 # http://stackoverflow.com/questions/8072755/

56 def oldmap(func, *iterables):

57 """

58 map(function, sequence[, sequence, ...]) -> list

60 Return a list of the results of applying the function to the

61 items of the argument sequence(s). If more than one sequence is

62 given, the function is called with an argument list consisting of

63 the corresponding item of each sequence, substituting None for

64 missing values when not all sequences have the same length. If

65 the function is None, return a list of the items of the sequence

66 (or a list of tuples if more than one sequence).

68 Test cases:

69 >>> oldmap(None, 'hello world')

70 ['h', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd']

72 >>> oldmap(None, range(4))

73 [0, 1, 2, 3]

75 More test cases are in test_past.test_builtins.

76 """

77 zipped = itertools.zip_longest(*iterables)

78 l = list(zipped)

79 if len(l) == 0:

80 return []

81 if func is None:

82 result = l

83 else:

84 result = list(starmap(func, l))

86 # Inspect to see whether it's a simple sequence of tuples

87 try:

88 if max([len(item) for item in result]) == 1:

89 return list(chain.from_iterable(result))

90 # return list(flatmap(func, result))

91 except TypeError as e:

92 # Simple objects like ints have no len()

93 pass

94 return result

96 ############################

97 ### For reference, the source code for Py2.7 map function:

98 # static PyObject *

99 # builtin_map(PyObject *self, PyObject *args)

100 # {

101 # typedef struct {

102 # PyObject *it; /* the iterator object */

103 # int saw_StopIteration; /* bool: did the iterator end? */

104 # } sequence;

105 #

106 # PyObject *func, *result;

107 # sequence *seqs = NULL, *sqp;

108 # Py_ssize_t n, len;

109 # register int i, j;

110 #

111 # n = PyTuple_Size(args);

112 # if (n < 2) {

113 # PyErr_SetString(PyExc_TypeError,

114 # "map() requires at least two args");

115 # return NULL;

116 # }

117 #

118 # func = PyTuple_GetItem(args, 0);

119 # n--;

120 #

121 # if (func == Py_None) {

122 # if (PyErr_WarnPy3k("map(None, ...) not supported in 3.x; "

123 # "use list(...)", 1) < 0)

124 # return NULL;

125 # if (n == 1) {

126 # /* map(None, S) is the same as list(S). */

127 # return PySequence_List(PyTuple_GetItem(args, 1));

128 # }

129 # }

130 #

131 # /* Get space for sequence descriptors. Must NULL out the iterator

132 # * pointers so that jumping to Fail_2 later doesn't see trash.

133 # */

134 # if ((seqs = PyMem_NEW(sequence, n)) == NULL) {

135 # PyErr_NoMemory();

136 # return NULL;

137 # }

138 # for (i = 0; i < n; ++i) {

139 # seqs[i].it = (PyObject*)NULL;

140 # seqs[i].saw_StopIteration = 0;

141 # }

142 #

143 # /* Do a first pass to obtain iterators for the arguments, and set len

144 # * to the largest of their lengths.

145 # */

146 # len = 0;

147 # for (i = 0, sqp = seqs; i < n; ++i, ++sqp) {

148 # PyObject *curseq;

149 # Py_ssize_t curlen;

150 #

151 # /* Get iterator. */

152 # curseq = PyTuple_GetItem(args, i+1);

153 # sqp->it = PyObject_GetIter(curseq);

154 # if (sqp->it == NULL) {

155 # static char errmsg[] =

156 # "argument %d to map() must support iteration";

157 # char errbuf[sizeof(errmsg) + 25];

158 # PyOS_snprintf(errbuf, sizeof(errbuf), errmsg, i+2);

159 # PyErr_SetString(PyExc_TypeError, errbuf);

160 # goto Fail_2;

161 # }

162 #

163 # /* Update len. */

164 # curlen = _PyObject_LengthHint(curseq, 8);

165 # if (curlen > len)

166 # len = curlen;

167 # }

168 #

169 # /* Get space for the result list. */

170 # if ((result = (PyObject *) PyList_New(len)) == NULL)

171 # goto Fail_2;

172 #

173 # /* Iterate over the sequences until all have stopped. */

174 # for (i = 0; ; ++i) {

175 # PyObject *alist, *item=NULL, *value;

176 # int numactive = 0;

177 #

178 # if (func == Py_None && n == 1)

179 # alist = NULL;

180 # else if ((alist = PyTuple_New(n)) == NULL)

181 # goto Fail_1;

182 #

183 # for (j = 0, sqp = seqs; j < n; ++j, ++sqp) {

184 # if (sqp->saw_StopIteration) {

185 # Py_INCREF(Py_None);

186 # item = Py_None;

187 # }

188 # else {

189 # item = PyIter_Next(sqp->it);

190 # if (item)

191 # ++numactive;

192 # else {

193 # if (PyErr_Occurred()) {

194 # Py_XDECREF(alist);

195 # goto Fail_1;

196 # }

197 # Py_INCREF(Py_None);

198 # item = Py_None;

199 # sqp->saw_StopIteration = 1;

200 # }

201 # }

202 # if (alist)

203 # PyTuple_SET_ITEM(alist, j, item);

204 # else

205 # break;

206 # }

207 #

208 # if (!alist)

209 # alist = item;

210 #

211 # if (numactive == 0) {

212 # Py_DECREF(alist);

213 # break;

214 # }

215 #

216 # if (func == Py_None)

217 # value = alist;

218 # else {

219 # value = PyEval_CallObject(func, alist);

220 # Py_DECREF(alist);

221 # if (value == NULL)

222 # goto Fail_1;

223 # }

224 # if (i >= len) {

225 # int status = PyList_Append(result, value);

226 # Py_DECREF(value);

227 # if (status < 0)

228 # goto Fail_1;

229 # }

230 # else if (PyList_SetItem(result, i, value) < 0)

231 # goto Fail_1;

232 # }

233 #

234 # if (i < len && PyList_SetSlice(result, i, len, NULL) < 0)

235 # goto Fail_1;

236 #

237 # goto Succeed;

238 #

239 # Fail_1:

240 # Py_DECREF(result);

241 # Fail_2:

242 # result = NULL;

243 # Succeed:

244 # assert(seqs);

245 # for (i = 0; i < n; ++i)

246 # Py_XDECREF(seqs[i].it);

247 # PyMem_DEL(seqs);

248 # return result;

249 # }

250

251 def oldrange(*args, **kwargs):

252 return list(builtins.range(*args, **kwargs))

253

254 def oldzip(*args, **kwargs):

255 return list(builtins.zip(*args, **kwargs))

256

257 filter = oldfilter

258 map = oldmap

259 range = oldrange

260 from functools import reduce

261 zip = oldzip

262 __all__ = ['filter', 'map', 'range', 'reduce', 'zip']

263

264else:

265 import __builtin__

266 # Python 2-builtin ranges produce lists

267 filter = __builtin__.filter

268 map = __builtin__.map

269 range = __builtin__.range

270 reduce = __builtin__.reduce

271 zip = __builtin__.zip

272 __all__ = []