pandas 在数据框 Python 中创建累积频率列
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/38891974/
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
提示：将鼠标放在中文语句上可以显示对应的英文。显示中英文
时间：2020-09-14 01:47:29 来源:igfitidea点击:
Creating a Cumulative Frequency Column in a Dataframe Python
提问by Fxs7576
I am trying to create a new column named 'Cumulative Frequency' in a data frame where it consists of all the previous frequencies to the frequency for the current row as shown here.
我正在尝试在数据框中创建一个名为“累积频率”的新列，其中包含所有以前的频率到当前行的频率，如此处所示。
What is the way to do this?
有什么方法可以做到这一点？
回答by EdChum
You want cumsum:
你想要cumsum：
df['Cumulative Frequency'] = df['Frequency'].cumsum()
Example:
例子：
In [23]:
df = pd.DataFrame({'Frequency':np.arange(10)})
df
Out[23]:
Frequency
0 0
1 1
2 2
3 3
4 4
5 5
6 6
7 7
8 8
9 9
In [24]:
df['Cumulative Frequency'] = df['Frequency'].cumsum()
df
Out[24]:
Frequency Cumulative Frequency
0 0 0
1 1 1
2 2 3
3 3 6
4 4 10
5 5 15
6 6 21
7 7 28
8 8 36
9 9 45
