[python]读写CSV基础笔记

csv库读入

import csv
with open('ap.csv', 'r') as f:
    reader = csv.reader(f)
    title = next(reader)
    print(title)
    step = []
    ap = []
    for r in reader:
        step.append((int(r[1])+1.0)/1000)
        ap.append(float(r[2])/100)
        
    #print(step, ap)
#print(len(ap))

matplotlib

import matplotlib.pyplot as plt
#fig = plt.figure()
plt.title("MAP", fontsize=16)
plt.plot(step, ap, c='blue',label='ap')
plt.xlabel('step(k)')
plt.ylabel('map')
plt.legend(loc='best')

csv.writerow()方法

with open('test.csv', 'w', encoding='utf-8', newline='') as f:
    writer =csv.writer(f)
    row_title = ['Step', 'Map']
    #构建头部
    writer.writerow(row_title) # 一行一行导入不适用于多种数据的情形
    

panda对csv文件进行写入操作

import pandas as pd
dataframe = pd.DataFrame({
    
    'step':step, 'ap':ap})
dataframe.to_csv('test.csv', index= False, sep=',')
pd.DataFrame({
    
    'step':step, 'ap':ap})