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用Python读取YAML文件会导致YAML.scanner.ScannerError:此处不允许映射值

pyyaml yaml python

Edamame · 技术社区 · 6 年前

import yaml
with open('/Users/edamame/my_logins/my_config.yaml', 'r') as infile:
    db_cfg = yaml.safe_load(infile)

它试图阅读 my_config.yaml :

database_info:
    username: edamame
    password: mypassword
    host: 1.2.3.4
    port: 3306
    database: mydb

但出现以下错误:

Traceback (most recent call last):
  File "/Users/edamame/my_project/extract_appointments.py", line 16, in <module>
    db_cfg = yaml.safe_load(infile)
  File "/Users/edamame/my_project/venv/lib/python3.6/site-packages/yaml/__init__.py", line 94, in safe_load
    return load(stream, SafeLoader)
  File "/Users/edamame/my_project/venv/lib/python3.6/site-packages/yaml/__init__.py", line 72, in load
    return loader.get_single_data()
  File "/Users/edamame/my_project/venv/lib/python3.6/site-packages/yaml/constructor.py", line 35, in get_single_data
    node = self.get_single_node()
  File "/Users/edamame/my_project/venv/lib/python3.6/site-packages/yaml/composer.py", line 36, in get_single_node
    document = self.compose_document()
  File "/Users/edamame/my_project/venv/lib/python3.6/site-packages/yaml/composer.py", line 55, in compose_document
    node = self.compose_node(None, None)
  File "/Users/edamame/my_project/venv/lib/python3.6/site-packages/yaml/composer.py", line 84, in compose_node
    node = self.compose_mapping_node(anchor)
  File "/Users/edamame/my_project/venv/lib/python3.6/site-packages/yaml/composer.py", line 127, in compose_mapping_node
    while not self.check_event(MappingEndEvent):
  File "/Users/edamame/my_project/venv/lib/python3.6/site-packages/yaml/parser.py", line 98, in check_event
    self.current_event = self.state()
  File "/Users/edamame/my_project/venv/lib/python3.6/site-packages/yaml/parser.py", line 428, in parse_block_mapping_key
    if self.check_token(KeyToken):
  File "/Users/edamame/my_project/venv/lib/python3.6/site-packages/yaml/scanner.py", line 116, in check_token
    self.fetch_more_tokens()
  File "/Users/edamame/my_project/venv/lib/python3.6/site-packages/yaml/scanner.py", line 220, in fetch_more_tokens
    return self.fetch_value()
  File "/Users/edamame/my_project/venv/lib/python3.6/site-packages/yaml/scanner.py", line 576, in fetch_value
    self.get_mark())
yaml.scanner.ScannerError: mapping values are not allowed here
  in "/Users/edamame/my_logins/my_config.yaml", line 5, column 9

以下是我的安装: 你知道我错过了什么吗?

2 回复 | 直到 6 年前

finefoot 6 年前

here :

你很可能有一些空格的差异,很可能在 port: 3306 线路。请注意,因为PyYAML早于最新的YAML标准(2009年的1.2),所以仍然考虑一些Unicode空白字符空白,尽管标准没有。

尝试将文件复制并粘贴到联机解析器中,一次一行,直到出现错误。这给你一个明确的指示哪条线错了。
使用YAML转储程序从Python中构造的数据转储所需的数据结构

import sys
import ruamel.yaml
from ruamel.yaml.comments import CommentedMap as cm

data = cm()
data['database_info'] = d = cm()
d['username'] = 'edamame'
d['password'] = 'mypassword'
d['host'] = '1.2.3.4'
d['port'] = 3306
d['database'] = 'mydb'


yaml = ruamel.yaml.YAML()
yaml.indent(mapping=4)

with open('my_config.yaml', 'w') as ofp:
    yaml.dump(data, ofp)

my_config.yaml :

database_info:
    username: edamame
    password: mypassword
    host: 1.2.3.4
    port: 3306
    database: mydb

(甚至)PyYAML应该能够读取的文件。

chris.mclennon 6 年前

我无法在运行python2和python3以及PyYAML==3.13的虚拟环境中使用几乎相同的代码进行复制。

>>> import yaml
>>> with open('sample.yaml', 'r') as infile:
...   db_cfg = yaml.safe_load(infile)
... 
>>> db_cfg
{'database_info': {'username': 'edamame', 'password': 'mypassword', 'host': '1.2.3.4', 'port': 3306, 'database': 'mydb'}}

您是否使用与示例相同的精确输入来获取此错误?