封装了两个库,简化一下代码。第一个不是最终版,先用着,比如说,L30那里关于请求的参数,只列出了常用的几个。到时候有需求了再改。
ohRequests.py
这个封装会对请求失败的URL默认重新请求3次,避免网络波动导致抓取失败。
import requests
from faker import Faker
class ohRequests(object):
def __init__(self, retries = 1):
self.faker = Faker()
self.GET = 'get'
self.POST = 'post'
self.RETRIES = retries
def __request(self,
method,
url,
headers = {},
cookies = None,
proxies = None,
params = None,
data = None,
timeout = 5):
# FIXME:
# 没有检测User-Agent, user-Agent之类的key名
headers['user-agent'] = self.faker.user_agent()
for i in range(self.RETRIES):
req_methond = requests.post if method == 'post' else requests.get
response = None
try:
response = req_methond(url,
headers = headers,
cookies = cookies,
proxies = proxies,
data = data,
timeout = timeout,
params = params
)
response.encoding = 'utf-8'
return response
except Exception:
print ('HTTPError, Status Code: {}'.format(response.status_code))
print ("Requests Error. Retry[{}], max retries[{}]".format(i+1, self.RETRIES))
return None
def get(self, url, **kwargs):
return self.__request('get', url, **kwargs)
def post(self, url, **kwargs):
return self.__request('post', url, **kwargs)
def faker_user_agent(self):
return self.faker.user_agent()
if __name__ == '__main__':
r = ohRequests()
req = r.get("http://www.baidu.com")
print (req)
ohSqlite3.py
import sqlite3
import os
class ohSqlite3(object):
""" APIs for using Sqlite3.
Attributes:
dbpath: the db file path for manipulation
conn: connection object returned from sqlite3.connect()
cursor: cursor object returned from conn
SHOW_SQL_STATEMENT: whether print sql statement, default False
"""
SHOW_SQL_STATEMENT = False
def __init__(self, dbpath):
"""inits ohSqlite3 with dbpath"""
self.dbpath = dbpath
self.conn = None
self.cursor = None
def __enter__(self):
self.connect()
return self
def __exit__(self, exc_type, exc_val, exc_tb):
self.close()
def connect(self):
"""init db connection
Raises:
sqlite3.Error: An error occurred when attempting to connect sqlite db.
"""
try:
self.conn = sqlite3.connect(self.dbpath)
except sqlite3.Error as e:
print ("Connect {} failed. Error: {}".foramt(self.dbpath, e.args[0]))
self.cursor = self.conn.cursor()
def execute(self, sql, args = None):
"""execute sql statement
Args:
sql: the sql statement to be executed
args: a tuple of fields to be added to sql, default None
Returns:
result of sql statement execution
Raises:
Exception: any errors occurred when executing sql statement
"""
if self.SHOW_SQL_STATEMENT:
print ("[SQL]{}".format(sql))
data = None
try:
if args:
self.cursor.execute(sql, args)
else:
self.cursor.execute(sql)
data = self.cursor.fetchall()
except Exception as e:
print (e, "[SQL]:" + sql.strip())
self.conn.rollback()
self.conn.commit()
if data:
return data
return None
def query(self, sql, args = None):
"""Same as execute(), different names"""
return self.execute(sql, args = None)
def close(self):
"""close all objects"""
self.cursor.close()
self.conn.close()
def unitest():
testdb = "ohSqlite3_test.db"
# test funcs
db = ohSqlite3(testdb)
db.connect()
db.execute("CREATE TABLE stocks (date text, trans text, symbol text, qty real, price real)")
db.execute("INSERT INTO stocks VALUES ('2006-01-05','BUY','RHAT',100,35.14)")
db.execute("INSERT INTO stocks VALUES ('2006-03-28', 'BUY', 'IBM', 1000, 45.00)")
db.execute("INSERT INTO stocks VALUES ('2006-04-05', 'BUY', 'MSFT', 1000, 72.00)")
db.execute("INSERT INTO stocks VALUES ('2006-04-06', 'SELL', 'IBM', 500, 53.00)")
assert 4 == db.execute("SELECT count(*) FROM stocks")[0][0]
db.execute("DROP TABLE stocks")
db.close()
# test __with__ statement
with ohSqlite3(testdb) as db:
db.query("CREATE TABLE stocks (date text, trans text, symbol text, qty real, price real)")
db.execute("INSERT INTO stocks VALUES ('2006-01-05','BUY','RHAT',100,35.14)")
db.execute("INSERT INTO stocks VALUES ('2006-03-28', 'BUY', 'IBM', 1000, 45.00)")
db.execute("INSERT INTO stocks VALUES ('2006-04-05', 'BUY', 'MSFT', 1000, 72.00)")
db.execute("INSERT INTO stocks VALUES ('2006-04-06', 'SELL', 'IBM', 500, 53.00)")
assert 4 == db.execute("SELECT count(*) FROM stocks")[0][0]
db.execute("DROP TABLE stocks")
os.remove(testdb)
if __name__ == "__main__":
unitest()
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