转载: Discord.py &Sympy(我想主要是discord.py )

Question

我在试着做一个数学不和谐机器人。我非常确定我的Sympy代码是正确的，只是discord.py太时髦了。

代码：

@client.command()
async def solve(ctx, equation):
    x, y, z, t = symbols('x y z t')
    k, m, n = symbols('k m n', integer=True)
    f, g, h = symbols('f g h', cls=Function)
    equation = equation.split("=")
    eqn = Eq(parse_expr(equation[0]), parse_expr(equation[1]))
    await ctx.send(f"```{solve(eqn)}```")

请假设我有所有必要的导入。

我得到了这个错误：

Ignoring exception in command solve:
Traceback (most recent call last):
  File "C:\Users\justi_zts5a0w\PycharmProjects\discord.py\venv\lib\site-packages\discord\ext\commands\core.py", line 85, in wrapped
ret = await coro(*args, **kwargs)
  File "math.py", line 42, in solve
    eqn = Eq(parse_expr(equation[0]), parse_expr(equation[1]))
  File "C:\Users\justi_zts5a0w\PycharmProjects\discord.py\venv\lib\site-packages\sympy\parsing\sympy_parser.py", line 1008, in parse_expr
return eval_expr(code, local_dict, global_dict)
  File "C:\Users\justi_zts5a0w\PycharmProjects\discord.py\venv\lib\site-packages\sympy\parsing\sympy_parser.py", line 902, in eval_expr
expr = eval(
  File "<string>", line 1
Integer (2 )+Integer (3 )Symbol ('x' )
                         ^
SyntaxError: invalid syntax

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\Users\justi_zts5a0w\PycharmProjects\discord.py\venv\lib\site-packages\discord\ext\commands\bot.py", line 903, in invoke
await ctx.command.invoke(ctx)
      File "C:\Users\justi_zts5a0w\PycharmProjects\discord.py\venv\lib\site-packages\discord\ext\commands\core.py", line 859, in invoke
await injected(*ctx.args, **ctx.kwargs)
  File "C:\Users\justi_zts5a0w\PycharmProjects\discord.py\venv\lib\site-packages\discord\ext\commands\core.py", line 94, in wrapped
raise CommandInvokeError(exc) from exc
discord.ext.commands.errors.CommandInvokeError: Command raised an exception: SyntaxError: invalid syntax (<string>, line 1)

Answer 1

从你得到的错误判断，问题不是来自discord.py，而是来自sympy。从代码的输出来看，这与引入参数equation的方式有关。

我在SymPy Live中做了以下调用，结果很好：

>>> from sympy.parsing.sympy_parser import parse_expr
>>> equation = 'x+1 = 0'
>>> equation = equation.split('=')
>>> eqn = Eq(parse_expr(equation[0]), parse_expr(equation[1]))
>>> print(eqn)
Eq(x + 1, 0)

但是，在您的代码中，它告诉您由于引入了语法，parse_expr无法正确计算表达式。确保您的输入公式具有有效的格式。