Python data flow operations-Python Tutorial-php.cn

Python data flow operations

巴扎黑

Release： 2018-05-16 14:53:35

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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

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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, &#39;r&#39;)    for line in fo:        print line

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

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

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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 &#39;failed&#39;
    else:        print &#39;success&#39;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 &#39;failed&#39;
    else:        print &#39;success&#39;getRC = lambda cur: cur.rowcount if hasattr(cur,&#39;rowcount&#39;)  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()

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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

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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, &#39;r&#39;)    for line in fo:        print line

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

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

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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 &#39;failed&#39;
    else:        print &#39;success&#39;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 &#39;failed&#39;
    else:        print &#39;success&#39;getRC = lambda cur: cur.rowcount if hasattr(cur,&#39;rowcount&#39;)  
    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()

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