Understand how xreplace works

【问题标题】：Understand how xreplace worksUnderstand how xreplace works
【发布时间】：2022-12-01 18:33:33
【问题描述】：

I'm trying to figure out how xreplace works. When I write

    from sympy import *
    my_list = [1234.5678, 22.333333]
    my_list.xreplace({n : round(n, 4) for n in expr.atoms(Number)})

I get an error:'list' object has no attribute 'xreplace'. What did I write wrong?

【问题讨论】：

标签： python sympy

【解决方案1】：

xreplace is a method of SymPy's objects. Your my_list is just an ordinary Python list, so it doesn't expose that method. What you can do it this:

from sympy import *
# Tuple is the SymPy version of a python tuple
my_list = Tuple(1234.5678, 22.333333)
my_list.xreplace({n : round(n, 4) for n in my_list.atoms(Number)})

【讨论】：