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v0.8.1
https://github.com/python/cpython
09 December 2020, 11:06:31 UTC
Revision 91fd1599358a1764e805f7ccfb6a8cb2ad558b7e authored by Benjamin Peterson on 10 May 2015, 17:13:10 UTC, committed by Benjamin Peterson on 10 May 2015, 17:13:10 UTC 
update pydoc-topics
1 parent 72c0141
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Tip revision: 91fd1599358a1764e805f7ccfb6a8cb2ad558b7e authored by Benjamin Peterson on 10 May 2015, 17:13:10 UTC
update pydoc-topics
Tip revision: 91fd159
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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