What to modify in the program such that ...

[sbabu]

What to change such that it only displays the information when executed directly, but it must not not display anything if it is imported as a module. The code works fine, but what to change ?

from math import pi

def circle_area(r):
    return pi * (r ** 2)

def circle_circumference(r):
    return 2 * pi * r

radius = float(input("Enter radius: "))
print("Area =", circle_area(radius))
print("Circumference =", circle_circumference(radius))

Thanks.

[ndc85430]

See this.

[sbabu]

Hi, ndc85430

Name of the script is ScriptEnv.py

from math import pi

def circle_area(r):
    return pi * (r ** 2)

def circle_circumference(r):
    return 2 * pi * r

radius = float(input("Enter radius: "))
print("Area =", circle_area(radius))
print("Circumference =", circle_circumference(radius))
def main():
    print("Running the main function")

if __name__ == "__main__":
    main()

This works.

Created another script with the name ScriptEnv2.py to call this main ScriptEnv.py

import ScriptEnv

ScriptEnv.circle_area()
ScriptEnv.circle_circumference()

Output:
>>> %Debug ScriptEnv2.py
Enter radius: 2
Area = 12.566370614359172
Circumference = 12.566370614359172
Traceback (most recent call last):
  File "E:\Python\Thony_Scripts\ScriptEnv2.py", line 3, in <module>
    ScriptEnv.circle_area()
TypeError: circle_area() missing 1 required positional argument: 'r'

The second script should not display anything but it's giving Area and Circumference and 1 error.

Thanks.

[ndc85430]

Your functions take arguments. Why aren't you passing anything when you call them?

[sbabu]

It's in the main script. ScriptEnv.py

#line no 9  
radius = float(input("Enter radius: "))

Thanks

[ndc85430]

On lines 3 and 6 of ScriptEnv.py, the functions are defined to take a single parameter, r. In ScriptEnv2.py, you're calling those functions on lines 3 and 4 without passing any arguments. Compare this with lines 10 and 11 in ScriptEnv.py - there you're passing radius to both functions. If a function takes arguments, you must supply them (assuming no defaults of course!). It's really as simple as that.

[jefsummers]

When you call the ScriptEnv.circle_area() function, you are only calling that particular function in the module, and the input line you have above does not get executed.

I suggest defining a class. Something like this (untested)

class geometry:

    from math import pi
    def __init__(self)
        self.go = False

    def circle_area(r):
        if go:
            return pi * (r ** 2)
 
    def circle_circumference(r):
        if go:
            return 2 * pi * r

Which is then called by

import geometry 
def main(g):
    print("Running the main function")
    radius = float(input("Enter radius: "))
    print("Area =", g.circle_area(radius))
    print("Circumference =", g.circle_circumference(radius))
 
if __name__ == "__main__":
    g = geometry()
    g.go = True
    main(g)

Dunder Main creates the geometry object and sets go to true, and passes the g object to main(). Function calls are then to the g object. If a geometry object is created elsewhere the default value for go is False, and nothing will print out. Malformed calls to the g object will still give error messages, as in the case of not passing a parameter.

---

One oops from not testing - need self. in front of the go's in the functions within the class

[buran]

This is going really into strange direction.
@jefsummers - what is the purpose of g.go property? and the class - as it is it defy the purpose of class.

to answer original question - as suggested by @ndc85430, you can use if __name__ == '__main__': block

from math import pi
 
def circle_area(r):
    return pi * (r ** 2)
 
def circle_circumference(r):
    return 2 * pi * r
 
if __name__ == "__main__":
    radius = float(input("Enter radius: "))
    print("Area =", circle_area(radius))
    print("Circumference =", circle_circumference(radius))

now, if it has to be class:

from math import pi

class Circle():
    def __init__(self, radius):
        self.radius = radius

    @property
    def area(self):
        return pi * (self.radius ** 2)
    
    @property
    def circumference(self):
        return 2 * pi * self.radius
 
if __name__ == "__main__":
    radius = float(input("Enter radius: "))
    circle = Circle(radius) # create instance of Circle class
    print("Area =", circle.area)
    print("Circumference =", circle.circumference)

in both cases nothing will happen if you import the module - functions and the class will be available to use in the other module, but the code in the if __name__ == '__main__': block will not be executed

[jefsummers]

@jefsummers - what is the purpose of g.go property? and the class - as it is it defy the purpose of class.

From the OP

but it must not not display anything if it is imported as a module.

So the go property is a flag, so that it does not display anything unless go is set to True. Someone importing as a module and accessing the functions directly will not get anything displayed. Running the file by itself will run properly.
@buran - in both of your solutions the functions can be called and will output even if the file is imported as a module.
Or maybe I misunderstood the question.

[buran]

yep, you misunderstood the question. In the OP original code if they import it in another module, then the 2 functions are accessible, but also lines 9-11 get executed at the time of the import. OP wants to prevent this from happening

only displays the information when executed directly, but it must not not display anything if it is imported as a module