python 标准库有二分查找的方法

import bisect
b =[-3,-2,-1,0,0,0,6,6,7]
left = bisect.bisect_left(b, 0)
right = bisect.bisect_right(b, 0, lo=left)
print(b[left-1],b[right] )

def bisect_left(a, x, lo=0, hi=None):
    """Return the index where to insert item x in list a, assuming a is sorted.

    The return value i is such that all e in a[:i] have e < x, and all e in
    a[i:] have e >= x.  So if x already appears in the list, a.insert(x) will
    insert just before the leftmost x already there.

    Optional args lo (default 0) and hi (default len(a)) bound the
    slice of a to be searched.
    """

    if lo < 0:
        raise ValueError('lo must be non-negative')
    if hi is None:
        hi = len(a)
    while lo < hi:
        mid = (lo+hi)//2
        if a[mid] < x: lo = mid+1
        else: hi = mid
    return lo

${data}=    json.dumps  ${data}