readline() 方法给出错误：AttributeError: 'tuple' object has no attribute 'readline'

Posted 2023-03-29

【中文标题】readline() 方法给出错误：AttributeError: \'tuple\' object has no attribute \'readline\'

【英文标题】：readline() method is giving error: AttributeError: 'tuple' object has no attribute 'readline'readline() 方法给出错误：AttributeError: 'tuple' object has no attribute 'readline'

【发布时间】：2021-04-09 03:44:03

【问题描述】：

我正在使用 jsonstreams.Stream 方法将数据输入到使用 Python 2.7 的 json 文件中，但是在尝试使用 readline() 方法从 PIPE 输入中读取数据时出现错误。错误指出 AttributeError: 'tuple' object has no attribute 'readline'。

branch_name = 'man/ashish_c/robotics'
days = '60'
json_output = 'output_log.json'

proc = subprocess.Popen(['git', 'log', branch_name, '--since="60 days ago"', '--pretty=%p\t%h\t%an\t%s\t%b'], shell=True, stdout=subprocess.PIPE)
stdout_value = proc.communicate()

with jsonstreams.Stream(jsonstreams.Type.array, filename=json_output) as output:
    while True:
        line = stdout_value.readline()
        if not line:
            break
        record = line.decode("utf-8").split("\t")
        with output.subobject() as output_e:
            output_e.write('merge', record[0])
            output_e.write('commit', record[1])
            output_e.write('author', record[2])
            output_e.write('title', record[3])
            output_e.write('body', record[4])

我希望 output_log.json 的内容看起来像这样：

[
    "commit": "3011203d", "merge": "e84d9feb", "author": "me", "title": "test commit", "body": "...",
    "commit": "5033203d", "merge": "u67d9feb", "author": "Dmitri", "title": "check infra", "body": ".."
    .....
]

【问题讨论】：

communicate() 返回一个 (stdout_data, stderr_data) 的元组。

【参考方案1】：

Popen.communicate() 返回一个 (stdout_data, stderr_data) 的元组。见https://docs.python.org/3/library/subprocess.html#subprocess.Popen.communicate

假设您想从stdout_data 读取尝试替换该行

stdout_value = proc.communicate()

与

stdout_value, stderr_value = proc.communicate()