python.py 文件源码

def python(expr, **settings):
    """Return Python interpretation of passed expression
    (can be passed to the exec() function without any modifications)"""

    printer = PythonPrinter(settings)
    exprp = printer.doprint(expr)

    result = ''
    # Returning found symbols and functions
    renamings = {}
    for symbolname in printer.symbols:
        newsymbolname = symbolname
        # Escape symbol names that are reserved python keywords
        if kw.iskeyword(newsymbolname):
            while True:
                newsymbolname += "_"
                if (newsymbolname not in printer.symbols and
                        newsymbolname not in printer.functions):
                    renamings[sympy.Symbol(
                        symbolname)] = sympy.Symbol(newsymbolname)
                    break
        result += newsymbolname + ' = Symbol(\'' + symbolname + '\')\n'

    for functionname in printer.functions:
        newfunctionname = functionname
        # Escape function names that are reserved python keywords
        if kw.iskeyword(newfunctionname):
            while True:
                newfunctionname += "_"
                if (newfunctionname not in printer.symbols and
                        newfunctionname not in printer.functions):
                    renamings[sympy.Function(
                        functionname)] = sympy.Function(newfunctionname)
                    break
        result += newfunctionname + ' = Function(\'' + functionname + '\')\n'

    if not len(renamings) == 0:
        exprp = expr.subs(renamings)
    result += 'e = ' + printer._str(exprp)
    return result