可视化数据

Question

假设我有一列作为性别包含像值的数据帧 -

male 
female 
female 
empty 
male 
female 

在条形图或饼图到的形式使用matplotlib如何可视化这个数据显示男性和女性的数量/比例？

Answer 1

最简单的选择可能是在列上使用value_count并将结果绘制为条形图。

import pandas as pd 
import matplotlib.pyplot as plt 

a = ["male","female", "female", "empty","male","female"] 
df = pd.DataFrame(a, columns= ["gender"]) 

df["gender"].value_counts().plot.bar() 

plt.show() 

它同样可以绘制一个饼图，

df["gender"].value_counts().plot.pie() 
plt.gca().set_aspect("equal") 

另一种选择，让更多的微调，是使用matplotlib如下：

import pandas as pd 
import matplotlib.pyplot as plt 

a = ["male","female", "female", "empty","male","female"] 
df = pd.DataFrame(a, columns= ["gender"]) 

labels = [] 
for i, dfi in enumerate(df.groupby(["gender"])): 
    labels.append(dfi[0]) 
    plt.bar(i, dfi[1].count(), label=dfi[0]) 
plt.xticks(range(len(labels)), labels) 
plt.legend() 
plt.show() 

Answer 2

使用本地熊猫功能：

a = ["male","female", "female", "empty","male","female"] 
df = pd.DataFrame(a, columns= ["gender"]) 
_ = df.groupby('gender').size().plot(kind='pie', legend=True)