我有一个字符串格式的SymPy表达式

-t*(a+b+c)/2

当以LaTeX形式(包括笔记本的LaTeX输出)进行漂亮打印时,它太高而且不容易阅读.

如何组合分数并将其放在括号之前？像这样：

(-t/2)*(a+b+c)

代码示例：

from sympy import symbols,Function,Derivative,var,init_printing,pprint,latex

init_printing()
def T(y):
    var('mu')
    return -1 / (2 * mu) * Derivative(y,x,x)

def V(y):
    var('x')
    V = Function('V',commutative=True)(x)
    return V * y

def K(y):
    var('x')
    K = Function('K',commutative=True)(x)
    return K * y

def a1(y):
    var('tau',positive=True)
    return tau * (T(y) + V(y))

def c(A,B):
    def comm(y):
        return A(B(y)) - B(A(y))
    return comm

var('x')
var('t')
f = Function('psi',commutative=False)

c1k = c(a1,K)
print(latex(c1k(f(x,t)).doit().simplify()))

打印和显示

- \frac{\tau \left(2 \frac{d}{d x} K{\left (x \right )} \frac{\partial}{\partial x} \psi{\left (x,t \right )} + \frac{d^{2}}{d x^{2}} K{\left (x \right )} \psi{\left (x,t \right )}\right)}{2 \mu}

我想在latex()和Jupyter笔记本中看到它们

-\frac{\tau}{2}\left(...\right)