我试图在Python中读取大型JSON文件(data.json)。由于该JSON文件具有多个JSON对象,并且在Python中将创建多个字典(字典数量未知),因此我使用了decoder.raw_decode()和generator。 以下是代码:
import json
import pprint
import io
import pprint
def parse():
with open('data.json',encoding='utf-8') as jfile:
try:
while True:
decoder = json.JSONDecoder()
obj, idx = decoder.raw_decode(jfile)
yield obj
except ValueError as e:
print(e)
pass
else:
print("aha")
def main():
imputd=parse()
if imputd:
while True:
try:
print(str(next(imputd)).readlines())
except StopIteration as e:
print(e)
break
main()
I get the error:
Traceback (most recent call last):
File "H:\Document\Python\j10.py", line 57, in <module>
main()
File "H:\Document\Python\j10.py", line 36, in main
print(str(next(imputd)).readlines())
File "H:\Document\Python\j10.py", line 21, in parse
obj, idx = decoder.raw_decode(jfile)
File "C:\Python34\lib\json\decoder.py", line 360, in raw_decode
obj, end = self.scan_once(s, idx)
TypeError: first argument must be a string, not _io.TextIOWrapper
我根据Martijn的答案进行了代码编辑:
import json
import io
file=open('data.json.txt')
def readin():
return file.read(2000)
def parse():
decoder = json.JSONDecoder()
buffer = ''
for chunk in iter(readin, ''):
buffer += chunk
while buffer:
try:
result, index = decoder.raw_decode(buffer)
yield result
buffer = buffer[index:]
except ValueError:
# Not enough data to decode, read more
break
def main():
imputd=parse()
if imputd:
while True:
try:
print(str(next(imputd)).readlines())
except StopIteration as e:
print(e)
break
main()
当我遇到 UnicodeError 时:
Traceback (most recent call last):
File "H:\Document\Python\j11.py", line 35, in <module>
main()
File "H:\Document\Python\j11.py", line 30, in main
print(str(next(imputd)).readlines())
File "H:\Document\Python\j11.py", line 14, in parse
for chunk in iter(readin, ''):
File "H:\Document\Python\j11.py", line 8, in readin
return file.read(2000)
File "C:\Python34\lib\encodings\cp1252.py", line 23, in decode
return codecs.charmap_decode(input,self.errors,decoding_table)[0]
UnicodeDecodeError: 'charmap' codec can't decode byte 0x9d in position 4217: character maps to <undefined>
open('data.json.text', encoding='utf8')
。如果这样还不行,你就必须找出编码是什么,但我没有上下文来帮助你。 - Martijn Pieters.lstrip()
来清除中间的空格。 - Martijn Pietersfor chunk in jfile:
(并可选择将所有名称为chunk
的用法替换为line
)来逐行读取文件。 - Martijn Pieters