pandas.DataFrame.to_json按行转json的方法
最近需要将csv文件转成DataFrame并以json的形式展示到前台，故需要用到Dataframe的to_json方法
to_json方法默认以列名为键，列内容为值，形成{col1:[v11,v21,v31…],col2:[v12,v22,v32],…}这种格式，但有时我们需要按行来转为json，形如这种格式[row1:{col1:v11,col2:v12,col3:v13…},row2:{col1:v21,col2:v22,col3:v23…}]
通过查找官网我们可以看到to_json方法有一个参数为orient，其参数说明如下：
orient:string
Series
defaultis‘index'
allowedvaluesare:{‘split','records','index'}
DataFrame
defaultis‘columns'
allowedvaluesare:{‘split','records','index','columns','values'}
TheformatoftheJSONstring
split:dictlike{index->[index],columns->[columns],data->[values]}
records:listlike[{column->value},…,{column->value}]
index:dictlike{index->{column->value}}
columns:dictlike{column->{index->value}}
values:justthevaluesarray
table:dictlike{‘schema':{schema},‘data':{data}}describingthedata,andthedatacomponentislikeorient='records'.
Changedinversion0.20.0
大致意思为：
如果是Series转json，默认的orient是'index'，orient可选参数有{‘split','records','index'}
如果是DataFrame转json，默认的orient是'columns'，orient可选参数有{‘split','records','index','columns','values'}
json的格式如下
split，样式为{index->[index],columns->[columns],data->[values]}
records，样式为[{column->value},…,{column->value}]
index，样式为{index->{column->value}}
columns，样式为{index->{column->value}}
values，数组样式
table，样式为{‘schema':{schema},‘data':{data}}，和records类似
看一下官网给的demo
df=pd.DataFrame([['a','b'],['c','d']],
index=['row1','row2'],
columns=['col1','col2'])
###########
split
###########
df.to_json(orient='split')
>'{"columns":["col1","col2"],
"index":["row1","row2"],
"data":[["a","b"],["c","d"]]}'
###########
index
###########
df.to_json(orient='index')
>'{"row1":{"col1":"a","col2":"b"},"row2":{"col1":"c","col2":"d"}}'
###########
records
###########
df.to_json(orient='index')
>'[{"col1":"a","col2":"b"},{"col1":"c","col2":"d"}]'
###########
table
###########
df.to_json(orient='table')
>'{"schema":{"fields":[{"name":"index","type":"string"},
{"name":"col1","type":"string"},
{"name":"col2","type":"string"}],
"primaryKey":"index",
"pandas_version":"0.20.0"},
"data":[{"index":"row1","col1":"a","col2":"b"},
{"index":"row2","col1":"c","col2":"d"}]}'
主要参考官网API：https://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.to_json.html
以上这篇pandas.DataFrame.to_json按行转json的方法就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持毛票票。