在Python中可视化CSV文件中的数据

CSV代表“逗号分隔值”。这意味着CSV文件中的数据（值）由分隔符分隔，即，逗号CSV文件中的数据以扩展名为. csv的表格格式存储。通常，CSV文件与Microsoft Excel工作表一起使用。CSV文件包含许多记录，数据分布在各行和各列中。在本文中，我们将在Python中可视化CSV文件中的数据。

要提取CSV文件中的数据，必须在我们的程序中导入CSV模块，如下所示：

import csv

with open('file.csv') as File:  
    Line_reader = csv.reader(File) 

例1：可视化条形图

以下CSV文件包含保存为“biostats. csv”的不同人员姓名、性别和年龄：

import matplotlib.pyplot as plt
import csv

x = []
y = []

with open('biostats.csv','r') as csvfile:
	plots = csv.reader(csvfile, delimiter = ',')
	
	for row in plots:
		x.append(row[0])
		y.append(int(row[2]))

plt.bar(x, y, color = 'g', width = 0.72, label = "Age")
plt.xlabel('Names')
plt.ylabel('Ages')
plt.title('Ages of different persons')
plt.legend()
plt.show()

输出

例2：可视化折线图

import matplotlib.pyplot as plt
import csv

x = []
y = []

with open('Weatherdata.csv','r') as csvfile:
	lines = csv.reader(csvfile, delimiter=',')
	for row in lines:
		x.append(row[0])
		y.append(int(row[1]))

plt.plot(x, y, color = 'g', linestyle = 'dashed',
		marker = 'o',label = "Weather Data")

plt.xticks(rotation = 25)
plt.xlabel('Dates')
plt.ylabel('Temperature(°C)')
plt.title('Weather Report', fontsize = 20)
plt.grid()
plt.legend()
plt.show()

输出

例3：可视化散点图

import matplotlib.pyplot as plt
import csv

Names = []
Values = []

with open('bldprs_measure.csv','r') as csvfile:
	lines = csv.reader(csvfile, delimiter=',')
	for row in lines:
		Names.append(row[0])
		Values.append(int(row[1]))

plt.scatter(Names, Values, color = 'g',s = 100)
plt.xticks(rotation = 25)
plt.xlabel('Names')
plt.ylabel('Values')
plt.title('Patients Blood Pressure Report', fontsize = 20)

plt.show()

输出

例4：可视化饼图

import matplotlib.pyplot as plt
import csv

Subjects = []
Scores = []

with open('SubjectMarks.csv', 'r') as csvfile:
	lines = csv.reader(csvfile, delimiter = ',')
	for row in lines:
		Subjects.append(row[0])
		Scores.append(int(row[1]))

plt.pie(Scores,labels = Subjects,autopct = '%.2f%%')
plt.title('Marks of a Student', fontsize = 20)
plt.show()

输出