import codecs
file_path = r'd:\\骅锋\\mall\\pages.json'
with codecs.open(file_path, 'r', 'utf-8') as f:
    text = f.read()

text = text.replace('custom\"\n      },{', 'custom\"\n      }\n    },\n    {')
with codecs.open(file_path, 'w', 'utf-8') as f:
    f.write(text)