Python 熊猫将多个组融为一列
原始数据帧:Python 熊猫将多个组融为一列,python,pandas,dataframe,transpose,melt,Python,Pandas,Dataframe,Transpose,Melt,原始数据帧: +----+----------+----------+----------+----------+ | ID | var1hrs | var2hrs | ind1var | ind2var | +----+----------+----------+----------+----------+ | 1 | 55 | 45 | 123 | 456 | | 2 | 48 | 60 | 331 |
+----+----------+----------+----------+----------+
| ID | var1hrs | var2hrs | ind1var | ind2var |
+----+----------+----------+----------+----------+
| 1 | 55 | 45 | 123 | 456 |
| 2 | 48 | 60 | 331 | 222 |
+----+----------+----------+----------+----------+
+----+------------+------+------+
| ID | type | hrs | ind |
+----+------------+------+------+
| 1 | primary | 55 | 123 |
| 1 | secondary | 45 | 456 |
| 2 | primary | 48 | 331 |
| 2 | secondary | 60 | 222 |
+----+------------+------+------+
目标数据帧:
+----+----------+----------+----------+----------+
| ID | var1hrs | var2hrs | ind1var | ind2var |
+----+----------+----------+----------+----------+
| 1 | 55 | 45 | 123 | 456 |
| 2 | 48 | 60 | 331 | 222 |
+----+----------+----------+----------+----------+
+----+------------+------+------+
| ID | type | hrs | ind |
+----+------------+------+------+
| 1 | primary | 55 | 123 |
| 1 | secondary | 45 | 456 |
| 2 | primary | 48 | 331 |
| 2 | secondary | 60 | 222 |
+----+------------+------+------+
我如何将多组变量融合到一个标签列中?变量名称中的“1”表示type=“primary”,而“2”表示type=“secondary” 修改列名称后,我们可以使用
wide\u to\u long
df.columns=df.columns.str[:4]
s=pd.wide_to_long(df,['var','ind'],i='ID',j='type').reset_index()
s=s.assign(type=s.type.map({'1':'primary','2':'secondary'})).sort_values('ID')
s
ID type var ind
0 1 primary 55 123
2 1 secondary 45 456
1 2 primary 48 331
3 2 secondary 60 222
(评论内联)
这或多或少是一种有效的方法,即使步骤有点复杂。到目前为止您尝试了什么?我很惊讶文档对这些函数的影响如此之大。。。这似乎很有用。@coldspeed同意!解释不清楚,很长一段时间以来,我一直在努力解决
后缀问题,我也很难弄清楚如何使用该函数!如果将“ind1var”和“ind2var”分别命名为“var1ind”和“var2ind”,您会怎么做?用[:4]切片所有列将导致重复的列名。@jerbear这是一个棘手的问题pd.wide\u-long(df,['var1','var2'],i='ID',j='drop',后缀='\w+')。取消堆栈(-2)。T
但您可以这样做