Pandas：使用变量从变量名称创建具有一行名称和列名称的数据框
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/44118416/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Pandas: Using variables to create dataframe with one row and column names from variable names
提问by stackoverflowuser2010
Suppose I have some variables in Python. I am trying to create a 1-row Pandas dataframe, where the column names are the variables' names and the values in the row are from the variables.
假设我在 Python 中有一些变量。我正在尝试创建一个 1 行的 Pandas 数据框，其中列名是变量的名称，行中的值来自变量。
For example, if I have this code:
例如，如果我有这个代码：
pi = 3.142
e = 2.718
phi = 1.618
I would like a dataframe that conceptually looks like this:
我想要一个概念上看起来像这样的数据框：
pi e phi
0 3.142 2.718 1.618
I tried the following, but everything is in one column, and the variable names are not added:
我尝试了以下操作，但所有内容都在一列中，并且未添加变量名称：
df = pd.DataFrame(data=[pi, e, phi])
df
# 0
# 0 3.140
# 1 2.718
# 2 1.618
Note that I'm trying to replicate the behavior of some of my older R code.
请注意，我正在尝试复制一些旧 R 代码的行为。
pi <- 3.142
e <- 2.718
phi <- 1.618
df <- data.frame(pi, e, phi)
df
# pi e phi
# 1 3.142 2.718 1.618
采纳答案by Scott Boston
I think you were looking for this format:
我认为您正在寻找这种格式：
pd.DataFrame([[pi,e,phi]],columns=['pi','e','phi'])
Output:
输出：
pi e phi
0 3.142 2.718 1.618
回答by Allen
#Reference columns names only once and column order is retained.
pd.concat([pd.DataFrame(data=[eval(k)],columns=[k]) for k in ['pi','e','phi']],axis=1)
Out[1226]:
pi e phi
0 3.142 2.718 1.618
回答by lmo
You can use a list and dictionary like this
您可以使用这样的列表和字典
df = pd.DataFrame([{'pi':pi, 'e':e, 'phi':phi}])
which returns
返回
df
Out[5]:
e phi pi
0 2.718 1.618 3.142
to preserve the column order, you can use the columns argument:
要保留列顺序，您可以使用 columns 参数：
df = pd.DataFrame([{'pi':pi, 'e':e, 'phi':phi}], columns=['pi', 'e', 'phi'])
which returns
返回
df
Out[9]:
pi e phi
0 3.142 2.718 1.618
Additional rows would go into separate dictionaries like this:
其他行将进入单独的字典，如下所示：
df = pd.DataFrame([{'pi':pi, 'e':e, 'phi':phi}, {'pi':2, 'e':3, 'phi':1}])
