原生c代码

i = j = 0;
while (maxcount-- > 0) {
    /* Increment counter past all leading whitespace in 
       the string. */
    while (i < str_len && STRINGLIB_ISSPACE(str[i]))
        i++;
    /* if string only contains whitespace, break. */
    if (i == str_len) break;

    /* After leading white space, increment counter 
       while the character is not a whitespace. 
       If this ends before i == str_len, it points to 
       a white space character. */
    j = i; i++;
    while (i < str_len && !STRINGLIB_ISSPACE(str[i]))
        i++;
#ifndef STRINGLIB_MUTABLE
    /* Case where no split should be done, return the string. */
    if (j == 0 && i == str_len && STRINGLIB_CHECK_EXACT(str_obj)) {
        /* No whitespace in str_obj, so just use it as list[0] */
        Py_INCREF(str_obj);
        PyList_SET_ITEM(list, 0, (PyObject *)str_obj);
        count++;
        break;
    }
#endif
    /* Make the split based on the incremented counters. */
    SPLIT_ADD(str, j, i);

Python中路径分割split的源代码

实现效果:
传入路径,eg. C:\Users\Actions\PycharmProjects\myAlgorithm
返回
head=C:\Users\Actions\PycharmProjects, tail=myAlgorithm

分析

程序的大致思路
1.先判断传入的路径的合法性
2.提取路径中的分隔符/
3.提取路径中倒数第一个分隔符的位置,构建head<带分隔符的路径名>和tail<文件名>
4.去除head两边的分隔符<一是为了判断head是否为空,二是为了判断head不会全部由分隔符构成的特殊情况>
5.返回head和tail