pig 中的python udf错误

Question

我正在尝试在 Pig 中的 python udf 下面运行

@outputSchema("word:chararray")
def get(s):
    out = s.lower()
    return out;

我收到以下错误:

  File "/home/test.py", line 3, in get
    out = s.lower()
AttributeError: 'NoneType' object has no attribute 'lower'

Answer 1

您应该处理 s 为 none 的情况。在大多数examples such as :

from pig_util import outputSchema

@outputSchema('decade:chararray')
def decade(year):
    """
    Get the decade, given a year.

    e.g. for 1998 -> '1990s'
    """
    try:
        base_decade_year = int(year) - (int(year) % 10)
        decade_str = '%ss' % base_decade_year
        print 'input year: %s, decade: %s' % (year, decade_str)
        return decade_str
    except ValueError:
        return None

您需要处理值为None的情况。因此，一种可能的解决方法是尝试:

@outputSchema("word:chararray")
def get(s):
    if s is None:
        return None
    return str(s).lower()