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v0.5.1
https://github.com/python/cpython
09 December 2020, 11:06:31 UTC
Revision 700c8fe2bac53ae4417a97da6c536f0da71ee060 authored by Tim Golden on 27 April 2014, 15:39:33 UTC, committed by Tim Golden on 27 April 2014, 15:39:33 UTC 
Issue #9291 Add ACKS & NEWS
1 parent 3c5816f
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Tip revision: 700c8fe2bac53ae4417a97da6c536f0da71ee060 authored by Tim Golden on 27 April 2014, 15:39:33 UTC
Issue #9291 Add ACKS & NEWS
Tip revision: 700c8fe
atof.c 

/* 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;
}
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