请参考下面的代码片段来理解os.path。加入(a, b)

a = '/home/user.name/foo/'
b = '/bar/file_name.extension'

print(os.path.join(a, b))
>>> /bar/file_name.extension

OR

a = '/home/user.name/foo'
b = '/bar/file_name.extension'
print(os.path.join(a, b))
>>> /bar/file_name.extension

但是,当

a = '/home/user.name/foo/'
b = 'bar/file_name.extension'

print(os.path.join(a, b))
>>> /bar/file_name.extension

OR

a = '/home/user.name/foo'
b = 'bar/file_name.extension'
print(os.path.join(a, b))
>>> /home/user.name/foo/bar/file_name.extension

只使用new_sandbox试试

os.path.join('/home/build/test/sandboxes/', todaystr, 'new_sandbox')

像这样，去掉多余的斜杠

root="/home"
os.path.join(root,"build","test","sandboxes",todaystr,"new_sandbox")

os.path.join("a", *"/b".split(os.sep))
'a/b'

更完整的版本:

import os

def join (p, f, sep = os.sep):
    f = os.path.normpath(f)
    if p == "":
        return (f);
    else:
        p = os.path.normpath(p)
        return (os.path.join(p, *f.split(os.sep)))

def test (p, f, sep = os.sep):
    print("os.path.join({}, {}) => {}".format(p, f, os.path.join(p, f)))
    print("        join({}, {}) => {}".format(p, f, join(p, f, sep)))

if __name__ == "__main__":
    # /a/b/c for all
    test("\\a\\b", "\\c", "\\") # optionally pass in the sep you are using locally
    test("/a/b", "/c", "/")
    test("/a/b", "c")
    test("/a/b/", "c")
    test("", "/c")
    test("", "c")

不要在路径组件的开头使用正斜杠，除非指向根目录:

os.path.join('/home/build/test/sandboxes', todaystr, 'new_sandbox')

参见:http://docs.python.org/library/os.path.html#os.path.join

Os.path.join()可以与os.path.sep一起使用来创建一个绝对路径，而不是相对路径。

os.path.join(os.path.sep, 'home','build','test','sandboxes',todaystr,'new_sandbox')