TypeError: can only concatenate str (not “int“) to str

Posted 2021-10-29 Data+Science+Insight

TypeError: can only concatenate str (not "int") to str

目录

TypeError: can only concatenate str (not "int") to str

问题：

解决：

#其他示例

完整错误：

---

问题：

#gp字段原本为int型；cheid字段为str型；

#转为object直接相加是有问题的；

#不转换直接相加也是有问题的；

df_dict.info()
# df = df.loc[0:206000].astype('float32',errors = 'ignore')
#df_dict['GP'] = df_dict['GP'].astype('object')
#or
df_dict['ID'] = df_dict['CHEID'] + df_dict['GP'] 

解决：

.astype('str')

df_dict.info()
# df = df.loc[0:206000].astype('float32',errors = 'ignore')
df_dict['GP'] = df_dict['GP'].astype('str')

df_dict['ID'] = df_dict['CHEID'] + df_dict['GP'] 

#其他示例

#如果字段都是str型
df["period"] = df["Year"] + df["quarter"]

#如果不是str型，那么转换后再相加也不迟；
df["period"] = df["Year"].astype(str) + df["quarter"]

完整错误：

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
D:\\anaconda\\lib\\site-packages\\pandas\\core\\ops\\array_ops.py in _na_arithmetic_op(left, right, op, is_cmp)
    141     try:
--> 142         result = expressions.evaluate(op, left, right)
    143     except TypeError:

D:\\anaconda\\lib\\site-packages\\pandas\\core\\computation\\expressions.py in evaluate(op, a, b, use_numexpr)
    234             # error: "None" not callable
--> 235             return _evaluate(op, op_str, a, b)  # type: ignore[misc]
    236     return _evaluate_standard(op, op_str, a, b)

D:\\anaconda\\lib\\site-packages\\pandas\\core\\computation\\expressions.py in _evaluate_standard(op, op_str, a, b)
     68     with np.errstate(all="ignore"):
---> 69         return op(a, b)
     70 

TypeError: can only concatenate str (not "int") to str

During handling of the above exception, another exception occurred:

TypeError                                 Traceback (most recent call last)
<ipython-input-208-94f0d1210a8f> in <module>
      2 # df = df.loc[0:206000].astype('float32',errors = 'ignore')
      3 df_dict['GP'] = df_dict['GP'].astype('object')
----> 4 df_dict['ID'] = df_dict['CHEID'] + df_dict['GP']

D:\\anaconda\\lib\\site-packages\\pandas\\core\\ops\\common.py in new_method(self, other)
     63         other = item_from_zerodim(other)
     64 
---> 65         return method(self, other)
     66 
     67     return new_method

D:\\anaconda\\lib\\site-packages\\pandas\\core\\arraylike.py in __add__(self, other)
     87     @unpack_zerodim_and_defer("__add__")
     88     def __add__(self, other):
---> 89         return self._arith_method(other, operator.add)
     90 
     91     @unpack_zerodim_and_defer("__radd__")

D:\\anaconda\\lib\\site-packages\\pandas\\core\\series.py in _arith_method(self, other, op)
   4996         lvalues = extract_array(self, extract_numpy=True)
   4997         rvalues = extract_array(other, extract_numpy=True)
-> 4998         result = ops.arithmetic_op(lvalues, rvalues, op)
   4999 
   5000         return self._construct_result(result, name=res_name)

D:\\anaconda\\lib\\site-packages\\pandas\\core\\ops\\array_ops.py in arithmetic_op(left, right, op)
    187     else:
    188         with np.errstate(all="ignore"):
--> 189             res_values = _na_arithmetic_op(lvalues, rvalues, op)
    190 
    191     return res_values

D:\\anaconda\\lib\\site-packages\\pandas\\core\\ops\\array_ops.py in _na_arithmetic_op(left, right, op, is_cmp)
    147             #  will handle complex numbers incorrectly, see GH#32047
    148             raise
--> 149         result = _masked_arith_op(left, right, op)
    150 
    151     if is_cmp and (is_scalar(result) or result is NotImplemented):

D:\\anaconda\\lib\\site-packages\\pandas\\core\\ops\\array_ops.py in _masked_arith_op(x, y, op)
     89         if mask.any():
     90             with np.errstate(all="ignore"):
---> 91                 result[mask] = op(xrav[mask], yrav[mask])
     92 
     93     else:

TypeError: can only concatenate str (not "int") to str

参考：Combine two columns of text in pandas dataframe

参考：python