Question

I am a beginner of python and have a question, very confusing for me. If I define a function first but within the function I have to use a variable which is defined in another function below, can I do it like this? Or how can I import the return things of another function into a function? for example:

def hello(x,y):     good=hi(iy,ix)     'then do somethings,and use the parameter'good'.'     return something  def hi(iy,ix):     'code'     return good 

Answer 1

The scope of functions hello and hi are entirely different. They do not have any variables in common.

Note that the result of calling hi(x,y) is some object. You save that object with the name good in the function hello.

The variable named good in hello is a different variable, unrelated to the variable named good in the function hi.

They’re spelled the same, but the exist in different namespaces. To prove this, change the spelling the good variable in one of the two functions, you’ll see that things still work.

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Edit. Follow-up: ‘so what should i do if i want use the result of hi function in hello function?’

Nothing unusual. Look at hello closely.

def hello(x,y):     fordf150 = hi(y,x)     'then do somethings,and use the variable 'fordf150'.'     return something  def hi( ix, iy ):     'compute some value, good.'     return good 

Some script evaluates hello( 2, 3).

1. Python creates a new namespace for the evaluation of hello.

2. In hello, x is bound to the object 2. Binding is done position order.

3. In hello, y is bound to the object 3.

4. In hello, Python evaluates the first statement, fordf150 = hi( y, x ), y is 3, x is 2.

   a. Python creates a new namespace for the evaluation of hi.

   b. In hi, ix is bound to the object 3. Binding is done position order.

   c. In hi, iy is bound to the object 2.

   d. In hi, something happens and good is bound to some object, say 3.1415926.

   e. In hi, a return is executed; identifying an object as the value for hi. In this case, the object is named by good and is the object 3.1415926.

   f. The hi namespace is discarded. good, ix and iy vanish. The object (3.1415926), however, remains as the value of evaluating hi.

5. In hello, Python finishes the first statement, fordf150 = hi( y, x ), y is 3, x is 2. The value of hi is 3.1415926.

   a. fordf150 is bound to the object created by evaluating hi, 3.1415926.

6. In hello, Python moves on to other statements.

7. At some point something is bound to an object, say, 2.718281828459045.

8. In hello, a return is executed; identifying an object as the value for hello. In this case, the object is named by something and is the object 2.718281828459045.

9. The namespace is discarded. fordf150 and something vanish, as do x and y. The object (2.718281828459045), however, remains as the value of evaluating hello.

Whatever program or script called hello gets the answer.