chore: 添加虚拟环境到仓库

- 添加 backend_service/venv 虚拟环境
- 包含所有Python依赖包
- 注意：虚拟环境约393MB，包含12655个文件

backend_service/venv/lib/python3.13/site-packages/mpmath/usertools.py

@@ -0,0 +1,93 @@
+
+def monitor(f, input='print', output='print'):
+    """
+    Returns a wrapped copy of *f* that monitors evaluation by calling
+    *input* with every input (*args*, *kwargs*) passed to *f* and
+    *output* with every value returned from *f*. The default action
+    (specify using the special string value ``'print'``) is to print
+    inputs and outputs to stdout, along with the total evaluation
+    count::
+
+        >>> from mpmath import *
+        >>> mp.dps = 5; mp.pretty = False
+        >>> diff(monitor(exp), 1)   # diff will eval f(x-h) and f(x+h)
+        in  0 (mpf('0.99999999906867742538452148'),) {}
+        out 0 mpf('2.7182818259274480055282064')
+        in  1 (mpf('1.0000000009313225746154785'),) {}
+        out 1 mpf('2.7182818309906424675501024')
+        mpf('2.7182808')
+
+    To disable either the input or the output handler, you may
+    pass *None* as argument.
+
+    Custom input and output handlers may be used e.g. to store
+    results for later analysis::
+
+        >>> mp.dps = 15
+        >>> input = []
+        >>> output = []
+        >>> findroot(monitor(sin, input.append, output.append), 3.0)
+        mpf('3.1415926535897932')
+        >>> len(input)  # Count number of evaluations
+        9
+        >>> print(input[3]); print(output[3])
+        ((mpf('3.1415076583334066'),), {})
+        8.49952562843408e-5
+        >>> print(input[4]); print(output[4])
+        ((mpf('3.1415928201669122'),), {})
+        -1.66577118985331e-7
+
+    """
+    if not input:
+        input = lambda v: None
+    elif input == 'print':
+        incount = [0]
+        def input(value):
+            args, kwargs = value
+            print("in  %s %r %r" % (incount[0], args, kwargs))
+            incount[0] += 1
+    if not output:
+        output = lambda v: None
+    elif output == 'print':
+        outcount = [0]
+        def output(value):
+            print("out %s %r" % (outcount[0], value))
+            outcount[0] += 1
+    def f_monitored(*args, **kwargs):
+        input((args, kwargs))
+        v = f(*args, **kwargs)
+        output(v)
+        return v
+    return f_monitored
+
+def timing(f, *args, **kwargs):
+    """
+    Returns time elapsed for evaluating ``f()``. Optionally arguments
+    may be passed to time the execution of ``f(*args, **kwargs)``.
+
+    If the first call is very quick, ``f`` is called
+    repeatedly and the best time is returned.
+    """
+    once = kwargs.get('once')
+    if 'once' in kwargs:
+        del kwargs['once']
+    if args or kwargs:
+        if len(args) == 1 and not kwargs:
+            arg = args[0]
+            g = lambda: f(arg)
+        else:
+            g = lambda: f(*args, **kwargs)
+    else:
+        g = f
+    from timeit import default_timer as clock
+    t1=clock(); v=g(); t2=clock(); t=t2-t1
+    if t > 0.05 or once:
+        return t
+    for i in range(3):
+        t1=clock();
+        # Evaluate multiple times because the timer function
+        # has a significant overhead
+        g();g();g();g();g();g();g();g();g();g()
+        t2=clock()
+        t=min(t,(t2-t1)/10)
+    return t