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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def which_bin(exes):
    '''
    Scan over some possible executables and return the first one that is found
    '''
    if not isinstance(exes, Iterable):
        return None
    for exe in exes:
        path = which(exe)
        if not path:
            continue
        return path
    return None