将字典列表打印到文件

Question

Python 3.6

我有一个生成字典列表的程序。

如果我将它打印到屏幕上：

print(json.dumps(output_lines, indent=4, separators=(',', ': ')))

打印出来的和我想看到的一模一样：

[
    {
        "runts": 0,     
        "giants": 0,     
        "throttles": 0,
        "input errors": 0,
        "CRC": 0,
        "frame": 0,
        "overrun": 0,
        "ignored": 0,
        "watchdog": 0,
        "pause input": 0,
        "input packets with dribble condition detected": 0,
        "underruns": 0,
        "output errors": 0,
        "collisions": 0,
        "interface resets": 2,
        "babbles": 0,
        "late collision": 0,
        "deferred": 0,
        "lost carrier": 0,
        "no carrier": 0,
        "PAUSE output": 0,
        "output buffer failures": 0,
        "output buffers swapped out": 0
    },
    {
        "runts": 0,
        "giants": 0,
        "throttles": 0,
        "input errors": 0,
        "CRC": 0,
        "frame": 0,
        "overrun": 0,
        "ignored": 0,
        "watchdog": 0,
        "pause input": 0,
        "input packets with dribble condition detected": 0,
        "underruns": 0,
        "output errors": 0,
        "collisions": 0,
        "interface resets": 2,
        "babbles": 0,
        "late collision": 0,
        "deferred": 0,
        "lost carrier": 0,
        "no carrier": 0,
        "PAUSE output": 0,
        "output buffer failures": 0,
        "output buffers swapped out": 0
    },

但是如果我尝试将其打印到文件中：

outputfile = ("d:\mark\python\Projects\error_detect\" + hostname)
# print(json.dumps(output_lines, indent=4, separators=(',', ': ')))
output_lines.append(json.dumps(output_lines, indent=4, separators=(',', ': ')))
del output_lines[-1]
with open(outputfile, 'w') as f:
    json.dump(output_lines, f)

该文件是一大行文本。

我希望文件中的格式与打印到屏幕时的格式相同。

我不明白为什么我会丢失格式。

Answer 1

尝试简单地输出格式化的 json.dumps，而不是再次通过 json.dump 运行。

with open(outputfile, 'w') as f:
    f.write(output_lines)

Answer 2

我想你只需要 json.dump 和 indent 就可以了：

outputfile = ("d:\mark\python\Projects\error_detect\" + hostname)
# print(json.dumps(output_lines, indent=4, separators=(',', ': ')))
# output_lines.append(json.dumps(output_lines, indent=4, separators=(',', ': ')))
# del output_lines[-1]
with open(outputfile, 'w') as f:
    json.dump(output_lines, f, indent=4, separators=(',', ': '))

格式化为字符串然后重新运行转储到字符串上对我来说没有多大意义。

Answer 3

假设您的程序生成了这个词典列表

>>> list_of_dicts = [dict(zip(list(range(2)),list(range(2)))), dict(zip(list(range(2)),list(range(2))))]
>>> list_of_dicts
[{0: 0, 1: 1}, {0: 0, 1: 1}]

你能做的是

>>> import json
>>> str_object = json.dumps(list_of_dicts, indent=4)
>>> repr(str_object)
'[\n    {\n        "0": 0, \n        "1": 1\n    }, \n    {\n        "0": 0, \n        "1": 1\n    }\n]'
>>> str_object
[
    {
        "0": 0, 
        "1": 1
    }, 
    {
        "0": 0, 
        "1": 1
    }
]

现在你可以写str_object

>>> with open(outputfile, 'w') as f:
        f.write(str_object)

这使得文件中的格式与您将其打印到屏幕上时的格式保持一致。

将字典列表打印到文件

Print a list of dictionaries to a file

python

json

python-3.6