Home  >  Article  >  Backend Development  >  Python data flow operations

Python data flow operations

巴扎黑
巴扎黑Original
2018-05-16 14:53:354644browse

Python file or folder operations

shutilThis module provides many advanced multi-file and multi-file collection operations, especially support for file copying and deletion. function.
1. Folder and file operations

import shutil 
shutil.copyfile(src, dst)   
 复制文件src的内容到文件dst,dst必须是完整的目标文件名,如果dst已经存在,它将会被替换 
shutil.copy(src, dst)   
 复制文件src到文件或文件夹dst。如果dst是一个文件夹,与src相同名字的文件在dst下被创建或重写。 
shutil.copytree(src, dst, symlinks=False, ignore=None) 
 递归的复制src下的整个目录到文件夹dst,dst不能是已经存在的,如果不存在,它将会被创建。 
shutil.rmtree(path) 
 删除path整个目录树内容 
os.rmdir(path)、 
 删除文件夹path,path必须是空文件夹,否则报OSError错误 
shutil.move(src, dst) 
 递归的移动src到另一个位置dst,src可以是一个文件或一个文件夹

2, traverse each file under the folder

import osnames = os.listdir(src)for name in names:
    srcname = os.path.join(src, name)
    fo = open(srcname, 'r')    for line in fo:        print line

3, determine whether the folder exists, create it if it does not exist

if not os.path.exists(FILE_PATH):        os.makedirs(FILE_PATH)

Python connection to MySQL and basic operations

def get_conn():
    import MySQLdb    try:
        conn=MySQLdb.connect(host=HOST,user=USER,passwd=PASSWORD, port=PORT, db=DBNAME, charset=CHARSET)        return conn    except MySQLdb.Error,e:        print "Mysql Error %d: %s" % (e.args[0], e.args[1])# 插入操作def insert_one(cur,sql,value):
    res =  cur.execute(sql ,value)    # 插入成功,res 返回值为1
    if  1 != res :        print 'failed'
    else:        print 'success'def insert_many(cur,sql,values):
    res =  cur.executemany(sql ,values)    # 插入成功,res 返回值为1
    if  1 != res :        print 'failed'
    else:        print 'success'getRC = lambda cur: cur.rowcount if hasattr(cur,'rowcount')  else -1# 更新操作def update(cur,sql):
    cur.execute(sql)    return getRC(cur)# 删除操作def delete(cur,sql):
    cur.execute(sql)    return getRC(cur)# 只获取一条记录,返回的是一个元组def fetch_one(cur,sql):
    count = cur.execute(sql)
    result = cur.fetchone()    return result# 获取多条数据;返回的是二维元组def fetch_all(cur,sql):
    count = cur.execute(sql)
    results = cur.fetchall()    return results# 提交的完成操作def finish(conn):
    conn.commit()
    conn.close()

Python file or folder operations

shutilThis module provides many advanced multi-file and multi-file collection operations. In particular, functions that support file copying and deletion are provided.
1. Folder and file operations

import shutil 
shutil.copyfile(src, dst)   
 复制文件src的内容到文件dst,dst必须是完整的目标文件名,如果dst已经存在,它将会被替换 
shutil.copy(src, dst)   
 复制文件src到文件或文件夹dst。如果dst是一个文件夹,与src相同名字的文件在dst下被创建或重写。 
shutil.copytree(src, dst, symlinks=False, ignore=None) 
 递归的复制src下的整个目录到文件夹dst,dst不能是已经存在的,如果不存在,它将会被创建。 
shutil.rmtree(path) 
 删除path整个目录树内容 
os.rmdir(path)、 
 删除文件夹path,path必须是空文件夹,否则报OSError错误 
shutil.move(src, dst) 
 递归的移动src到另一个位置dst,src可以是一个文件或一个文件夹

2, traverse each file under the folder

import osnames = os.listdir(src)for name in names:
    srcname = os.path.join(src, name)
    fo = open(srcname, 'r')    for line in fo:        print line

3, determine whether the folder exists, create it if it does not exist

if not os.path.exists(FILE_PATH):        os.makedirs(FILE_PATH)

Python connection to MySQL and basic operations

def get_conn():
    import MySQLdb    try:
        conn=MySQLdb.connect(host=HOST,user=USER,passwd=PASSWORD, port=PORT, db=DBNAME, charset=CHARSET)        
        return conn    except MySQLdb.Error,e:        
        print "Mysql Error %d: %s" % (e.args[0], e.args[1])# 插入操作def insert_one(cur,sql,value):
    res =  cur.execute(sql ,value)    # 插入成功,res 返回值为1
    if  1 != res :        print 'failed'
    else:        print 'success'def insert_many(cur,sql,values):
    res =  cur.executemany(sql ,values)    # 插入成功,res 返回值为1
    if  1 != res :        print 'failed'
    else:        print 'success'getRC = lambda cur: cur.rowcount if hasattr(cur,'rowcount')  
    else -1# 更新操作def update(cur,sql):
    cur.execute(sql)    return getRC(cur)# 删除操作def delete(cur,sql):
    cur.execute(sql)    return getRC(cur)# 只获取一条记录,返回的是一个元组def fetch_one(cur,sql):
    count = cur.execute(sql)
    result = cur.fetchone()    return result# 获取多条数据;返回的是二维元组def fetch_all(cur,sql):
    count = cur.execute(sql)
    results = cur.fetchall()    return results# 提交的完成操作def finish(conn):
    conn.commit()
    conn.close()

The above is the detailed content of Python data flow operations. For more information, please follow other related articles on the PHP Chinese website!

Statement:
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn