PyPackage01---Pandas09_从字典创建dataframe

Intro

很简单的需求，不多说，直接看代码

import pandas as

pd.__version__

'0.23.4'

Demo

dict1 = {"x1": 1, "x2": 2, "x3": 3}
pd.DataFrame(dict1)

---------------------------------------------------------------------------

ValueError                                Traceback (most recent call last)

<ipython-input-5-6aaa44730903> in <module>()
      1 dict1 = {"x1": 1, "x2": 2, "x3": 3}
----> 2 pd.DataFrame(dict1)


D:\code\anaconda\lib\site-packages\pandas\core\frame.py in __init__(self, data, index, columns, dtype, copy)
    346                                  dtype=dtype, copy=copy)
    347         elif isinstance(data, dict):
--> 348             mgr = self._init_dict(data, index, columns, dtype=dtype)
    349         elif isinstance(data, ma.MaskedArray):
    350             import numpy.ma.mrecords as mrecords


D:\code\anaconda\lib\site-packages\pandas\core\frame.py in _init_dict(self, data, index, columns, dtype)
    457             arrays = [data[k] for k in keys]
    458 
--> 459         return _arrays_to_mgr(arrays, data_names, index, columns, dtype=dtype)
    460 
    461     def _init_ndarray(self, values, index, columns, dtype=None, copy=False):


D:\code\anaconda\lib\site-packages\pandas\core\frame.py in _arrays_to_mgr(arrays, arr_names, index, columns, dtype)
   7354     # figure out the index, if necessary
   7355     if index is None:
-> 7356         index = extract_index(arrays)
   7357 
   7358     # don't force copy because getting jammed in an ndarray anyway


D:\code\anaconda\lib\site-packages\pandas\core\frame.py in extract_index(data)
   7391 
   7392         if not indexes and not raw_lengths:
-> 7393             raise ValueError('If using all scalar values, you must pass'
   7394                              ' an index')
   7395 


ValueError: If using all scalar values, you must pass an index

卡卡报了一堆错，这个错误可以通过修改dict解决，即value改成list

dict2 = {"x1": [1], "x2": [2], "x3": [3]}
pd.DataFrame(dict2)

如果不修改原始数据咋整

dict1 = {"x1": 1, "x2": 2, "x3": 3}
pd.DataFrame([dict1])

Ref

​​[1] https://stackoverflow.com/questions/18837262/convert-python-dict-into-a-dataframe​​

                                2020-05-18 于南京市江宁区九龙湖