pandas 从多个列表创建一个熊猫数据框
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create a pandas data frame from several lists
提问by user3495042
My function outputs a list, for instance when I type:
我的函数输出一个列表，例如当我输入：
My_function('TV', 'TV_Screen')
it outputs the following:
它输出以下内容：
['TV', 1, 'TV_Screen', 0.04, 'True']
Now, my TV is made of several parts, such as speaker, transformer, etc., I can keep running my function for each part, and for instance change 'TV_Screen' for 'TV_Speaker', or 'TV_transformer', etc.
现在，我的电视由几个部分组成，例如扬声器、变压器等，我可以继续为每个部分运行我的功能，例如将“TV_Screen”更改为“TV_Speaker”或“TV_transformer”等。
The alternative is to create a list with all the part, such as:
另一种方法是创建一个包含所有零件的列表，例如：
TV_parts = ['TV_Screen', 'TV_Speaker', 'TV_transformer']
What I am trying to get is a pandas data frame with 5 columns (because my function outputs 5 variables, see above the section "it outputs the following:") and in this case 3 rows (one of each for 'TV_Screen', 'TV_Speaker', and 'TV_transformer'). Basically, I want the following to be in a data frame:
我想要得到的是一个有 5 列的 Pandas 数据框（因为我的函数输出 5 个变量，请参阅上面的“它输出以下内容：”部分），在这种情况下，有 3 行（“TV_Screen”中的每一行，“ TV_Speaker”和“TV_transformer”）。基本上，我希望以下内容在数据框中：
['TV', 1, 'TV_Screen', 0.04, 'True']
['TV', 9, 'TV_Speaker', 0.56, 'True']
['TV', 3, 'TV_transformer', 0.80, 'False']
I know I need a for loop somewhere, but I am not sure how to create this data frame. Could you please help? (I can change the output of my function to be a pd.Series or something else that would work better).
我知道我在某处需要一个 for 循环，但我不确定如何创建这个数据框。能否请你帮忙？（我可以将函数的输出更改为 pd.Series 或其他更好的东西）。
Thanks!
谢谢！
回答by andrewwowens
If you have many arrays, it may be worth converting them into a numpy matrix first and then converting them into a dataframe.
如果您有许多数组，可能值得先将它们转换为 numpy 矩阵，然后再将它们转换为数据帧。
import pandas as pd
import numpy as np
a = ['TV', 1, 'TV_Screen', 0.04, 'True']
b = ['TV', 9, 'TV_Speaker', 0.56, 'True']
c = ['TV', 3, 'TV_transformer', 0.80, 'False']
matrix = np.matrix([a,b,c])
df = pd.DataFrame(data=matrix)
回答by elyase
You can do it like this:
你可以这样做：
def My_function(part):
# prepare result
result = ['TV', 1, part, 0.04, 'True'] # for testing
return result
TV_parts = ['TV_Screen', 'TV_Speaker', 'TV_transformer']
df = pd.DataFrame([My_function(part) for part in TV_parts])
>>> df
0 1 2 3 4
0 TV 1 TV_Screen 0.04 True
1 TV 1 TV_Speaker 0.04 True
2 TV 1 TV_transformer 0.04 True
