Mercurial > cpython-lru_cache-weakref
view Python/atof.c @ 55822:6758bf2002da legacy-trunk
#5101: add back tests to test_funcattrs that were lost during unittest conversion, and make some PEP8 cleanups.
| author | Georg Brandl <georg@python.org> |
|---|---|
| date | Fri, 04 Sep 2009 11:19:34 +0000 |
| parents | 2dea40e40d9d |
| children | fd25030223b0 |
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/* Just in case you haven't got an atof() around... This one doesn't check for bad syntax or overflow, and is slow and inaccurate. But it's good enough for the occasional string literal... */ #include "pyconfig.h" #include <ctype.h> double atof(char *s) { double a = 0.0; int e = 0; int c; while ((c = *s++) != '\0' && isdigit(c)) { a = a*10.0 + (c - '0'); } if (c == '.') { while ((c = *s++) != '\0' && isdigit(c)) { a = a*10.0 + (c - '0'); e = e-1; } } if (c == 'e' || c == 'E') { int sign = 1; int i = 0; c = *s++; if (c == '+') c = *s++; else if (c == '-') { c = *s++; sign = -1; } while (isdigit(c)) { i = i*10 + (c - '0'); c = *s++; } e += i*sign; } while (e > 0) { a *= 10.0; e--; } while (e < 0) { a *= 0.1; e++; } return a; }
