Return self ** other [ % modulo]. With two arguments, compute self**other. With three arguments, compute (self**other) % modulo. For the three argument form, the following restrictions on the arguments hold: - all three arguments must be integral
(self, other, modulo=None, context=None)
| 2248 | return _dec_from_triple(0, str_xc+'0'*zeros, xe-zeros) |
| 2249 | |
| 2250 | def __pow__(self, other, modulo=None, context=None): |
| 2251 | """Return self ** other [ % modulo]. |
| 2252 | |
| 2253 | With two arguments, compute self**other. |
| 2254 | |
| 2255 | With three arguments, compute (self**other) % modulo. For the |
| 2256 | three argument form, the following restrictions on the |
| 2257 | arguments hold: |
| 2258 | |
| 2259 | - all three arguments must be integral |
| 2260 | - other must be nonnegative |
| 2261 | - either self or other (or both) must be nonzero |
| 2262 | - modulo must be nonzero and must have at most p digits, |
| 2263 | where p is the context precision. |
| 2264 | |
| 2265 | If any of these restrictions is violated the InvalidOperation |
| 2266 | flag is raised. |
| 2267 | |
| 2268 | The result of pow(self, other, modulo) is identical to the |
| 2269 | result that would be obtained by computing (self**other) % |
| 2270 | modulo with unbounded precision, but is computed more |
| 2271 | efficiently. It is always exact. |
| 2272 | """ |
| 2273 | |
| 2274 | if modulo is not None: |
| 2275 | return self._power_modulo(other, modulo, context) |
| 2276 | |
| 2277 | other = _convert_other(other) |
| 2278 | if other is NotImplemented: |
| 2279 | return other |
| 2280 | |
| 2281 | if context is None: |
| 2282 | context = getcontext() |
| 2283 | |
| 2284 | # either argument is a NaN => result is NaN |
| 2285 | ans = self._check_nans(other, context) |
| 2286 | if ans: |
| 2287 | return ans |
| 2288 | |
| 2289 | # 0**0 = NaN (!), x**0 = 1 for nonzero x (including +/-Infinity) |
| 2290 | if not other: |
| 2291 | if not self: |
| 2292 | return context._raise_error(InvalidOperation, '0 ** 0') |
| 2293 | else: |
| 2294 | return _One |
| 2295 | |
| 2296 | # result has sign 1 iff self._sign is 1 and other is an odd integer |
| 2297 | result_sign = 0 |
| 2298 | if self._sign == 1: |
| 2299 | if other._isinteger(): |
| 2300 | if not other._iseven(): |
| 2301 | result_sign = 1 |
| 2302 | else: |
| 2303 | # -ve**noninteger = NaN |
| 2304 | # (-0)**noninteger = 0**noninteger |
| 2305 | if self: |
| 2306 | return context._raise_error(InvalidOperation, |
| 2307 | 'x ** y with x negative and y not an integer') |
no test coverage detected