string.py

def one_space(s):
    s = s.strip()
    while s.find('  ') > -1:
        s = s.replace('  ', ' ')
    return s
    

def to_str(v):
    if isinstance(v, date):
        return dmy(v)
    if isinstance(v, datetime):
        return dmyhms(v)
    if v == 0:
        return '0'
    if isinstance(v, str):
        return v.strip()
    if isinstance(v, bool):
        return v and '1' or '0'
    return v and str(v) or ''
    

def dict_to_str(d):
    r = {}
    for key in d:
        val = d[key]        
        r[key] = to_str(val)
    return r