我正在尝试在id字段（这是一个字符串uuid）上加入两个熊猫数据帧。我收到值错误：

ValueError：您正在尝试合并object和int64列。如果要继续，则应使用pd.concat

代码如下。我正在尝试按照尝试合并2个数据帧将字段转换为字符串，但得到ValueError但错误仍然存​​在。请注意，pdf是由火花产生的，dataframe.toPandas()而outputPdf是由字典创建的。

pdf.id = pdf.id.apply(str)
outputsPdf.id = outputsPdf.id.apply(str)
inOutPdf = pdf.join(outputsPdf, on='id', how='left', rsuffix='fs')

pdf.dtypes
id         object
time      float64
height    float32
dtype: object

outputsPdf.dtypes
id         object
labels    float64
dtype: object

我该如何调试？完整回溯：

ValueError                                Traceback (most recent call last)
<ipython-input-13-deb429dde9ad> in <module>()
     61 pdf['id'] = pdf['id'].astype(str)
     62 outputsPdf['id'] = outputsPdf['id'].astype(str)
---> 63 inOutPdf = pdf.join(outputsPdf, on=['id'], how='left', rsuffix='fs')
     64 
     65 # idSparkDf = spark.createDataFrame(idPandasDf, schema=StructType([StructField('id', StringType(), True),

~/miniconda3/lib/python3.6/site-packages/pandas/core/frame.py in join(self, other, on, how, lsuffix, rsuffix, sort)
   6334         # For SparseDataFrame's benefit
   6335         return self._join_compat(other, on=on, how=how, lsuffix=lsuffix,
-> 6336                                  rsuffix=rsuffix, sort=sort)
   6337 
   6338     def _join_compat(self, other, on=None, how='left', lsuffix='', rsuffix='',

~/miniconda3/lib/python3.6/site-packages/pandas/core/frame.py in _join_compat(self, other, on, how, lsuffix, rsuffix, sort)
   6349             return merge(self, other, left_on=on, how=how,
   6350                          left_index=on is None, right_index=True,
-> 6351                          suffixes=(lsuffix, rsuffix), sort=sort)
   6352         else:
   6353             if on is not None:

~/miniconda3/lib/python3.6/site-packages/pandas/core/reshape/merge.py in merge(left, right, how, on, left_on, right_on, left_index, right_index, sort, suffixes, copy, indicator, validate)
     59                          right_index=right_index, sort=sort, suffixes=suffixes,
     60                          copy=copy, indicator=indicator,
---> 61                          validate=validate)
     62     return op.get_result()
     63

~/miniconda3/lib/python3.6/site-packages/pandas/core/reshape/merge.py in __init__(self, left, right, how, on, left_on, right_on, axis, left_index, right_index, sort, suffixes, copy, indicator, validate)
    553         # validate the merge keys dtypes. We may need to coerce
    554         # to avoid incompat dtypes
--> 555         self._maybe_coerce_merge_keys()
    556 
    557         # If argument passed to validate,

~/miniconda3/lib/python3.6/site-packages/pandas/core/reshape/merge.py in _maybe_coerce_merge_keys(self)
    984             elif (not is_numeric_dtype(lk)
    985                     and (is_numeric_dtype(rk) and not is_bool_dtype(rk))):
--> 986                 raise ValueError(msg)
    987             elif is_datetimelike(lk) and not is_datetimelike(rk):
    988                 raise ValueError(msg)