为什么在 Python Pandas dtype float64 上出现错误？

Question

I'm in a jupyter notebook on a Windows PC. I've read in a dataframe I'm calling tran as follows

tran = pd.read_csv("https://raw.githubusercontent.com/m1ngle/TRCount/main/TRCountUS.csv")

When I look at data types for the entire dataframe, it works great

tran.dtypes

FIPS             int64
State           object
YMTF             int64
MTFPer         float64
YFTM             int64
FTMPer         float64
YNB              int64
NBPer          float64
YTR              int64
YTRper         float64
NoTR             int64
NoTRPer        float64
DK               int64
DKPer          float64
DNAns            int64
DNAPer         float64
TotSurveyed      int64
StatePop         int64
TRPop            int64
dtype: object

When I attempt to call, or work with any of the float64 columns I get an error

tran['MTFPer'].dtype
KeyError                                  Traceback (most recent call last)
~\anaconda3\lib\site-packages\pandas\core\indexes\base.py in get_loc(self, key, method, tolerance)
   2645             try:
-> 2646                 return self._engine.get_loc(key)
   2647             except KeyError:

pandas\_libs\index.pyx in pandas._libs.index.IndexEngine.get_loc()

pandas\_libs\index.pyx in pandas._libs.index.IndexEngine.get_loc()

pandas\_libs\hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()

pandas\_libs\hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()

KeyError: 'MTFPer'

During handling of the above exception, another exception occurred:

KeyError                                  Traceback (most recent call last)
<ipython-input-85-2bd9c012f223> in <module>
----> 1 tran['MTFPer'].dtype

~\anaconda3\lib\site-packages\pandas\core\frame.py in __getitem__(self, key)
   2798             if self.columns.nlevels > 1:
   2799                 return self._getitem_multilevel(key)
-> 2800             indexer = self.columns.get_loc(key)
   2801             if is_integer(indexer):
   2802                 indexer = [indexer]

~\anaconda3\lib\site-packages\pandas\core\indexes\base.py in get_loc(self, key, method, tolerance)
   2646                 return self._engine.get_loc(key)
   2647             except KeyError:
-> 2648                 return self._engine.get_loc(self._maybe_cast_indexer(key))
   2649         indexer = self.get_indexer([key], method=method, tolerance=tolerance)
   2650         if indexer.ndim > 1 or indexer.size > 1:

pandas\_libs\index.pyx in pandas._libs.index.IndexEngine.get_loc()

pandas\_libs\index.pyx in pandas._libs.index.IndexEngine.get_loc()

pandas\_libs\hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()

pandas\_libs\hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()

KeyError: 'MTFPer'

This error does not occur when I work with any of the int64 dtypes.

tran['YMTF'].dtype
dtype('int64')

Can anyone help me out?

Answer 1

While reading the .csv file, pandas also read in the whitespace that came along with the columns. When I did tran[' MTFPer '].dtype instead of tran['MTFPer'].dtype , pandas gave me the correct answer.
Maybe clean up the data itself a little bit, or you could clean up the column names like so:

tran.columns = [c.strip() for c in tran.columns]