Using sympy's latex() function without calculating the input

问题

I want to get latex output from a sympy expression without calculating the expression. For instance if I do latex((2+3)/7) the output would be 5/7 (with latex), but what I am after is for it to just output (2+3)/7 with latex. Like this: \frac{2+3}{7}

回答1:

You can manually adjust the long_frac_ratio

long_frac_ratio: The allowed ratio of the width of the numerator to the width of the denominator before we start breaking off long fractions. The default value is 2.

>>> latex(e,long_frac_ratio=3)
'\\frac{2 + 3}{7}'

回答2:

You can try to sympify the expression with keyword evaluate=False:

>>> latex(S('(2+3)/7',evaluate=False))
'\\frac{1}{7} \\left(2 + 3\\right)'

回答3:

(better added as another answer)

Don't forget about the mode options:

>>> e = S('(2+3)/7', evaluate=False)
>>> latex(e,mode='inline')
'$\\left(2 + 3\\right) / 7$'
>>> latex(e,mode='plain')
'\\frac{1}{7} \\left(2 + 3\\right)'
>>> latex(e,mode='equation')
'\\begin{equation}\\frac{1}{7} \\left(2 + 3\\right)\\end{equation}'
>>> latex(e,mode='equation*')
'\\begin{equation*}\\frac{1}{7} \\left(2 + 3\\right)\\end{equation*}'

回答4:

Perhaps the fold_short_frac option is what you are looking for?

>>> latex(S('(2+3)/7',evaluate=False), fold_short_frac=True)
'\\left(2 + 3\\right) / 7'

Also, not sure what you mean about the evaluate=False not working for Mul. Perhaps you can give an example.

>>> S('2*3',evaluate=False)
2*3
>>> S('2*3/7',evaluate=False)
2*3/7

来源：https://stackoverflow.com/questions/28543995/using-sympys-latex-function-without-calculating-the-input