Why can't I do "import sys.argv[1]"?

Question

I created a module called parameter.py and wanted to import it using sys.argv as shown below.

import sys
from sys.argv[1] import *

But when I run the python file I get the following error:

python test.py parameter


File "test.py", line 17
    from sys.argv[1] import *
                 ^
    SyntaxError: invalid syntax

Why doesn't it work and what else can I do to make it work?

Answer 1

Variables are not allowed in import statement

import sys
__import__(sys.argv[1])

Global Import

import sys
globals().update(__import__(sys.argv[1]).__dict__)

Example Usage

import sys

sys.argv.append("math")
pi = __import__(sys.argv[-1]).pi
print(pi)

Or

import sys

sys.argv.append("math")
globals().update({k: v for k, v in __import__(sys.argv[-1]).__dict__.items() if not k.startswith("__")})
print(pi)
print(__name__)

Output

3.141592653589793
__main__