Python YAML hiera 以及双引号内的值如何？

Question

我有这个代码

python_data_struct = {
        'amazon_app_id': amazon_app_id,
        'librivox_rest_url': librivox_rest_url,
        'librivox_id': librivox_id,
        'top': top,
        'pacakge': 'junk',
        'version': 'junk',
        'password': password,
        'description': description,
        'long_description': long_description,
        'make_audiobook::sftp_script::appname': '\"%{::appname}\"'
}
try:
        myyaml = yaml.dump(python_data_struct)
except:
        e = sys.exc_info()[0]
        print "Error on %s Error [%s]" % ( librivox_rest_url, e )
        sys.exit(5)
write_file( myyaml, hiera_dir + '/' + appname + '.yaml' );

它输出如下所示的 yaml：

{amazon_app_id: junk, description: !!python/unicode ' Riley was an American writer
    known as the "Hoosier poet", and made a start writing newspaper verse in Hoosier
    dialect for the Indianapolis Journal in 1875. His favorite authors were Burns
    and Dickens. This collection of poems is a romanticized and mostly boy-centered
    paean to a 19th century rural American working-class childhood. (Summary by Val
    Grimm)', librivox_id: '1000', librivox_rest_url: 'https://librivox.org/api/feed/audiobooks/id/1000/extended/1/format/json',
  long_description: !!python/unicode "\n Riley was an American writer known as the\
    \ \"Hoosier poet\", and made a start writing newspaper verse in Hoosier dialect\
    \ for the Indianapolis Journal in 1875. His favorite authors were Burns and Dickens.\
    \ This collection of poems is a romanticized and mostly boy-centered paean to\
    \ a 19th century rural American working-class childhood. (Summary by Val Grimm)\n\
    \nThe \"Selected Riley Child-Rhymes\" App will not use up your data plan's minutes\
    \ by downloading the audio files (mp3) over and over. You will download load all\
    \ the data when you install the App. The \"Selected Riley Child-Rhymes\" App works\
    \ even in airplane mode and in places without Wi-Fi or phone network access! So\
    \ you can listen to your audio book anywhere anytime! The \"Selected Riley Child-Rhymes\"\
    \ App automatically pauses when you make or receive a phone call and automatically\
    \ resumes after the call ends. The \"Selected Riley Child-Rhymes\" App will continue\
    \ to play until you exit the App or pause the reading so it is perfect for listening\
    \ in bed, at the gym, or while driving into work.\" \n", 'make_audiobook::sftp_script::appname': '"%{::appname}"',
  pacakge: junk, password: junk, top: junk, version: junk}

很难看出，但有问题的特定键/值对是这个：

'make_audiobook::sftp_script::appname': '"%{::appname}"',

我需要它是这样的：

'make_audiobook::sftp_script::appname': "%{::appname}",

只是在%{::appname} 周围加上双引号我不知道在我的python 代码中要做什么。请帮忙:)

Answer 1

如果你想要一个 YAML 中的字符串，那么你只需要一个 Python 中的字符串：

python_data_struct = {
    'make_audiobook::sftp_script::appname': '%{::appname}'
}

print yaml.dump(python_data_struct)

这给了你：

{'make_audiobook::sftp_script::appname': '%{::appname}'}

或者等价的，default_flow_style=False:

make_audiobook::sftp_script::appname: '%{::appname}'

在 YAML 中 "a value" 使用双引号和 'a value' 使用单引号之间没有区别。这个：

my_key: 'my value'

还有这个：

my_key: "my value"

两者都将评估为完全相同的数据结构。

Answer 2

如果您需要控制 Python YAML 转储中的引号，我建议使用 ruamel.yaml（免责声明：我是该软件包的作者）

import sys
from ruamel import yaml

amazon_app_id = 'junk'
librivox_rest_url = 'https://librivox.org/api/feed/audiobooks/id/1000/extended/1/format/json'

python_data_struct = {
        'amazon_app_id': amazon_app_id,
        'librivox_rest_url': librivox_rest_url,
        'pacakge': 'junk',
        'version': 'junk',
        yaml.scalarstring.SingleQuotedScalarString('make_audiobook::sftp_script::appname'):
            yaml.scalarstring.DoubleQuotedScalarString('%{::appname}')
}

try:
    with open(hiera_dir + '/' + appname + '.yaml') as fp:
        yaml.round_trip_dump(python_data_struct, fp)
except Exception as e:
    print("Error on {} Error [{}]".format(librivox_rest_url, e))
    sys.exit(5)

给你：

librivox_rest_url: https://librivox.org/api/feed/audiobooks/id/1000/extended/1/format/json
version: junk
'make_audiobook::sftp_script::appname': "%{::appname}"
amazon_app_id: junk
pacakge: junk

请注意，默认情况下，PyYAML 会在嵌入了“:”的标量周围加上引号，即使该字符后面没有空格，尽管这不是必需的。

round_trip_dump()也没有使用第二个参数，（dump()也有这个参数）。不提供该参数并让 YAML 文件先在内存中构建是非常低效的。

我还更改了您的一些其他代码，除非您被困在 Python 2.6 左右，否则您应该 IMO 现代化您的语法。您可能还想查看键名（您的意思是“pacakge”吗？）