本文介绍了将Pandas DataFrame JSON列切成列的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我有一个数据框，其中包含两列JSON格式，如下所示:
I have a data frame which have two columns in JSON format, like this:
author biblio series
Mehrdad Vahabi {'volume': 68, 'month': 'January', {'handle':'RePEc:aka:aoecon', 'name': 'Oeconomica'}
'name': 'János Kornai',
'issue': 's', 'handle':
'n:v:68:y:2018:i',
'year': '2018',
'pages': '27-52', 'doi': ''}
Michael Bailey {'c_date': '2017', 'number': {'handle': '', 'name': ''}
'23608', 'handle': 'RePEc:nbr:
nberwo:23608', 'name': 'Measuring'}
我要我的数据框看起来像这样:
I Want to my data frame looks like this:
author biblio.volume biblio.month biblio.name biblio.issue biblio.handle bibilio.year biblio.pages biblio.doi biblio.c_date bibi¡lio.number series.handle series.name
Mehrdad Vahabi 68 January János Kornai s n:v:68:y:2018:i 2018 27-52 NA NA RePEc:aka:aoecon Oeconomica
Michael Bailey NA Na Meausuring NA nberwo:23608 NA NA NA 2017 23608
我尝试使用，但是没有人为我工作.
I try do it using the answers in this question, but no one works for me.
我该怎么办?
在@jezrael解决方案之后，我得到了:
Following the @jezrael solution I get this:
df1 = pd.DataFrame(df['biblio'].values.tolist())
df1.columns = 'biblio.'+ df1.columns
df2 = pd.DataFrame(df['series'].values.tolist())
df2.columns = 'series.'+ df2.columns
col = df.columns.difference(['biblio','series'])
df = pd.concat([df[col], df1, df2],axis=1)
print (df)
Traceback (most recent call last):
File "dfs.py", line 8, in <module>
df1.columns = 'bibliographic.'+ df1.columns
File "/Users/danielotero/anaconda3/lib/python3.6/site-
packages/pandas/core/indexes/range.py", line 583, in _evaluate_numeric_binop
other = self._validate_for_numeric_binop(other, op, opstr)
File "/Users/danielotero/anaconda3/lib/python3.6/site-
packages/pandas/core/indexes/base.py", line 3961, in
_validate_for_numeric_binop
raise TypeError("can only perform ops with scalar values")
TypeError: can only perform ops with scalar values
并使用json_normalize:
Traceback (most recent call last):
File "/Users/danielotero/anaconda3/lib/python3.6/site-packages/pandas/core/indexes/base.py", line 2525, in get_loc
return self._engine.get_loc(key)
File "pandas/_libs/index.pyx", line 117, in pandas._libs.index.IndexEngine.get_loc
File "pandas/_libs/index.pyx", line 139, in pandas._libs.index.IndexEngine.get_loc
File "pandas/_libs/hashtable_class_helper.pxi", line 1265, in pandas._libs.hashtable.PyObjectHashTable.get_item
File "pandas/_libs/hashtable_class_helper.pxi", line 1273, in pandas._libs.hashtable.PyObjectHashTable.get_item
KeyError: 0
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "dfs.py", line 7, in <module>
df = json_normalize(d)
File "/Users/danielotero/anaconda3/lib/python3.6/site-packages/pandas/io/json/normalize.py", line 192, in json_normalize
if any([isinstance(x, dict) for x in compat.itervalues(data[0])]):
File "/Users/danielotero/anaconda3/lib/python3.6/site-packages/pandas/core/frame.py", line 2139, in __getitem__
return self._getitem_column(key)
File "/Users/danielotero/anaconda3/lib/python3.6/site-packages/pandas/core/frame.py", line 2146, in _getitem_column
return self._get_item_cache(key)
File "/Users/danielotero/anaconda3/lib/python3.6/site-packages/pandas/core/generic.py", line 1842, in _get_item_cache
values = self._data.get(item)
File "/Users/danielotero/anaconda3/lib/python3.6/site-packages/pandas/core/internals.py", line 3843, in get
loc = self.items.get_loc(item)
File "/Users/danielotero/anaconda3/lib/python3.6/site-packages/pandas/core/indexes/base.py", line 2527, in get_loc
return self._engine.get_loc(self._maybe_cast_indexer(key))
File "pandas/_libs/index.pyx", line 117, in pandas._libs.index.IndexEngine.get_loc
File "pandas/_libs/index.pyx", line 139, in pandas._libs.index.IndexEngine.get_loc
File "pandas/_libs/hashtable_class_helper.pxi", line 1265, in pandas._libs.hashtable.PyObjectHashTable.get_item
File "pandas/_libs/hashtable_class_helper.pxi", line 1273, in pandas._libs.hashtable.PyObjectHashTable.get_item
KeyError: 0
在@Jhon H解决方案之后，我得到了:
Following the @Jhon H solution, I get this:
Traceback (most recent call last):
File "dfs.py", line 7, in <module>
jsonSeries = df[['bibliographic']].tolist()
File "/Users/danielotero/anaconda3/lib/python3.6/site-packages/pandas/core/generic.py", line 3614, in __getattr__
return object.__getattribute__(self, name)
AttributeError: 'DataFrame' object has no attribute 'tolist'
推荐答案
为每个dict列创建一个新的DataFrame，由构造函数和最后一个 concat 一起:
Create for each dict column new DataFrame by constructor and last concat all together:
df1 = pd.DataFrame(df['biblio'].values.tolist())
df1.columns = 'biblio.'+ df1.columns
df2 = pd.DataFrame(df['series'].values.tolist())
df2.columns = 'series.'+ df2.columns
col = df.columns.difference(['biblio','series'])
df = pd.concat([df[col], df1, df2],axis=1)
print (df)
author biblio.c_date biblio.doi biblio.handle \
0 Mehrdad Vahabi NaN n:v:68:y:2018:i
1 Michael Bailey 2017 NaN RePEc:nbr:nberwo:23608
biblio.issue biblio.month biblio.name biblio.number biblio.pages \
0 s January Janos Kornai NaN 27-52
1 NaN NaN Measuring 23608 NaN
biblio.volume biblio.year series.handle series.name
0 68.0 2018 RePEc:aka:aoecon Oeconomica
1 NaN NaN
如果输入为json，请使用 json_normalize :
If input is json is possible use json_normalize:
from pandas.io.json import json_normalize
d = [{"author":"Mehrdad Vahabi","biblio":{"volume":68,"month":"January","name":"Janos Kornai","issue":"s","handle":"n:v:68:y:2018:i","year":"2018","pages":"27-52","doi":""},"series":{"handle":"RePEc:aka:aoecon","name":"Oeconomica"}},{"author":"Michael Bailey","biblio":{"c_date":"2017","number":"23608","handle":"RePEc:nbr:nberwo:23608","name":"Measuring"},"series":{"handle":"","name":""}}]
df = json_normalize(d)
print (df)
author biblio.c_date biblio.doi biblio.handle \
0 Mehrdad Vahabi NaN n:v:68:y:2018:i
1 Michael Bailey 2017 NaN RePEc:nbr:nberwo:23608
biblio.issue biblio.month biblio.name biblio.number biblio.pages \
0 s January Janos Kornai NaN 27-52
1 NaN NaN Measuring 23608 NaN
biblio.volume biblio.year series.handle series.name
0 68.0 2018 RePEc:aka:aoecon Oeconomica
1 NaN NaN
字典是字符串是有问题的，因此首先必须使用ast.literal_eval进行转换:
There is problem your dictionaries are strings, so first is necessary use ast.literal_eval for convert:
import ast
df = pd.read_csv('probe.csv')
#print (df)
df1 = pd.DataFrame(df['bibliographic'].apply(ast.literal_eval).values.tolist())
df1.columns = 'bibliographic.'+ df1.columns
df2 = pd.DataFrame(df['series'].apply(ast.literal_eval).values.tolist())
df2.columns = 'series.'+ df2.columns
col = df.columns.difference(['bibliographic','series'])
df = pd.concat([df[col], df1, df2],axis=1)
这篇关于将Pandas DataFrame JSON列切成列的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！