How can I convert string to source code in python?

问题

As you see, ifinner is a string, so if I just write after if, always will be true. What can i do, to concert it to source code?

    x=2
    ifinner = "x==3"
    if ifinner:
        print("Yeah")
    else:
        print("It works!")

回答1:

You can use eval() function to evaluate Python source code.

Quoting the documentation:

eval(expression, globals=None, locals=None)

The arguments are a string and optional globals and locals. If provided, globals must be a dictionary. If provided, locals can be any mapping object.

回答2:

Try this:

exec ("%s == 3" % x)

For detailed info, read the documentation of eval and exec in python 2.x/3.x. A similar question was asked previously.Here's the link

来源：https://stackoverflow.com/questions/43878504/how-can-i-convert-string-to-source-code-in-python