pandas 排序和限制条形图上显示的条形数量
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Sort and limit number of bars to display on bargraph
提问by zelda1234
I have a dataset of traffic violations and want to display only the top 10 violations per month on a bargraph. Can I limit the number of bars after sorting values to display only the top 10? There are 42 different column names of traffic violations.
我有一个交通违规数据集，并且只想在条形图上显示每月前 10 次的违规行为。我可以在对值进行排序后限制条数以仅显示前 10 条吗？交通违章有42个不同的列名。
month_jan = df[df.MonthName == "Jan"]
month_jan[feature_cols].sum().sort_values(ascending=0).plot(kind='bar')
Feature_colsis a list of all 42 column names that correspond to traffic violations.
Feature_cols是与交通违规对应的所有 42 个列名称的列表。
Thanks!
谢谢！
采纳答案by mechanical_meat
This will work:
这将起作用：
month_jan[feature_cols].sum().sort_values(ascending=0)[:10].plot(kind='bar')
回答by ibab
Seriesobjects have a .headmethod, just like DataFrames (docs).
This allows you to select the top N items very elegantly with data.head(N).
Here's a complete working example:
Series对象有一个.head方法，就像DataFrames ( docs)。这使您可以非常优雅地选择前 N 个项目data.head(N)。这是一个完整的工作示例：
import pandas as pd
df = pd.DataFrame({
'feature1': [0, 1, 2, 3],
'feature2': [2, 3, 4, 5],
'MonthName': ['Jan', 'Jan', 'Jan', 'Feb']
})
feature_cols = ['feature1', 'feature2']
month_jan = df[df.MonthName == "Jan"]
top10 = month_jan[feature_cols].sum().sort_values(ascending=0).head(10)
top10.plot(kind='bar')
