import maya.cmds as cmds
import re
import glob, os
 
# – Define our search and replace
replace_this ='string you want to replace'
with_this = ""
# - Get your Project path
projectPath=cmds.workspace(q=True, rd=True)
scenesPath= projectPath+"scenes/"
# – Use a regex to do the substitution as that is very quick
regex = re.compile(replace_this)
os.chdir(scenesPath)
for root, dirs, files in os.walk(scenesPath):
    for file in files:
        if file.endswith(".ma"):
             print(root+'/'+file)
             filepath = root+'/'+file
             with open(filepath, "r") as read_stream:
                lines=read_stream.read()
                with open(filepath, "w") as write_stream:
                    write_stream.write(regex.sub(with_this, lines))
print "工作完成..."