retry function for `retry` times

robust_run.py

import functools
import sys

def robust(expected, retry=3):
    def wrapper(func):
        @functools.wraps(func)
        def robust_run(*args, **kw):
            n = 0;
            result = None
            while n < retry:
                try:
                    result = func(*args, **kw)
                except Exception as e:
                    print >>sys.stderr, 'Robust run exception:', e
                print 'Robust run(try=%d): %s with args %r %r: result=%r' % (n + 1, func.__name__, args, kw, result)
                if result == expected:
                    break
                n += 1
            if n == retry:
                print >>sys.stderr, 'Robust run(total_retry=%d): %s failed!' % (retry, func.__name__)
            return result
        return robust_run
    return wrapper

"""
  this is equal to:
  test = robust(0)(test)
"""
@robust(0)
def test(n):
    return n