从文本文件中提取变量的值

Question

以下是文本文件的片段 (txt.toml)：

value = 10.0
base = 14.0
outcome = 20.0
numbers = [12.0, 20.0]
input = false
Scheme = "default"
sigma = [1, 8, 11, 5]

我想访问变量“base”的值。我尝试了中的以下解决方案：

variable = {}
with open('txt.toml', 'r') as file:
    for line in file:
        name, value = line.replace(' ', '').strip('=')
        variable[name] = value
        
print(variable['base'])

抛出以下错误：

ValueError: too many values to unpack (expected 2)

我无法修复此错误。如何访问存储在变量“base”中的值？

Answer 1

您可以使用 str.partition() to extract the name and the value part separated by an "=". Then you can use str.strip() 删除空格。

variable = {}
with open('txt.toml', 'r') as file:
    for line in file:
        name, _, value = line.partition('=')
        variable[name.strip()] = value.strip()
        
print(variable['base'])

$ python3 src.py 
14.0

即使您的源数据中有空格，即使您的值中有多个等号 "="，此解决方案也有效

txt.toml

...
Scheme = "default value here = (12 == 12.0)"
...

代码

...
print(variable['Scheme'])

输出

$ python3 src.py 
"default value here = (12 == 12.0)"

Answer 2

使用 split 而不是 strip。

试试这个：

variable = {}
with open('txt.toml', 'r') as file:
    for line in file:
        name, value = line.replace(' ', '').split('=')
        variable[name] = value
        

variable

输出：

{'value': '10.0\n',
 'base': '14.0\n',
 'outcome': '20.0\n',
 'numbers': '[12.0,20.0]\n',
 'input': 'false\n',
 'Scheme': '"default"\n',
 'sigma': '[1,8,11,5]'}

Answer 3

您需要 split 字符串而不是 strip 字符串。 split returns 一个列表和 strip() returns 一个字符串，其中从字符串的任一侧删除了所需的子字符串。

.split 将根据分隔符将字符串拆分为列表，.strip() 从字符串的开头和开头剥离字符串。

variable = {}
with open('txt.toml', 'r') as file:
    for line in file:
        name, value = line.replace(' ', '').split('=')
        variable[name] = value
        
print(variable['base'])

Answer 4

with open("txt.toml") as fd:
    lines = fd.read().splitlines()
lines = [line.split("=") for line in lines]
result =  {i[0].strip() : i[1].strip() for i in lines}
print(result)
print(result['base'])

从文本文件中提取变量的值

Extract the value of a variable from a text file

python

file-io

split

replace