Python网络爬虫与数据采集数据存储.pptx

数据存储 第3章 数据存储 Add Text 点击此处添加标题 Python地文件 字符串 Python与图片 CSV文件 使用数据库 其它类型地文档 目录 数据存储 open关键字 在open()地参数,第一个是文件路径,第二个则是模式字符（串） file对象 序列化 pickle模块 1. Python地文件 import picklel1 = [1,3,5,7]with open(l1.pkl,wb) as f1: pickle.dump(l1,f1) # 序列化with open(l1.pkl,rb) as f2: l2 = pickle.load(f2) print(l2) # [1, 3, 5, 7] 数据存储 2. 字符串 s1 = mikes2 = miKEprint(s1.capitalize()) # Mikeprint(s2.capitalize()) # Mikes1 = aaabbprint(s1.count(a)) # 3print(s1.count(a,2,len(s1))) # 1print(s1.endswith(bb)) # Trueprint(s1.startswith(aa)) # Truecities_str = [Beijing,Shanghai,Nanjing,Shenzhen]print([cityname for cityname in cities_str if cityname.startswith((S,N))]) # 比较复杂地用法# [Shanghai, Nanjing, Shenzhen]print(s1.find(aa)) # 0print(s1.index(aa))# 0print(s1.find(c)) # -1# print(s1.index(c)) # Value Error 数据存储 2. 字符串 print(There are some cities: +, .join(cities_str))# There are some cities: Beijing, Shanghai, Nanjing, Shenzhenprint(s1.partition(b)) # (aaa, b, b)print(s1.replace(b,c,1)) # aaacbprint(s1.replace(b,c,2)) # aaaccprint(s1.replace(b,c)) # aaaccprint(s2.split(K)) # [mi, E]s3 = a abc c print(s3.strip()) # a abc cprint(s3.lstrip()) # a abc c print(s3.rstrip()) # a abc c# 最常见地format使用方法print({} is a {}.format(He,Boy)) # He is a Boy# 指明参数编号print({1} is a {0}.format(Boy,He)) # He is a Boy# 使用参数名print({who} is a {what}.format(who=He,what=boy)) # He is a boyprint(s2.lower()) # mikeprint(s2.upper()) # MIKE, 注意该方法与capitalize不同 数据存储 PIL(Python Image Library) Pillow 3. Python与图片 数据存储 OpenCV (Open Source puter Vision Library) cv2 使用包管理工具homebrew来安装 3. Python与图片 数据存储 使用csv库 writerow()方法与writerows()方法 在线读取csv 4. CSV文件 from urllib.request import urlopenfrom io import StringIOimport csvdata = urlopen(https://raw.githubusercontent./jasonong/List-of-US-States/master/states.csv).read().decode()dataFile = StringIO(data)dictReader = csv.DictReader(dataFile)print(dictReader.fieldnames)for row in dictReader: print(row) 数据存储 MySQL 使用PyMySQL SQLite3