一次函数中的python运行代码

Question

I am trying to make a variable in Python go up by one continuously, but inside a function. What I am using is something like this:

def func1():
   def set1():
      x=5
      y=10
   ##lots of code
   x+=1
   y+=1

def func2():
   while True:
      func1()
set1()
func2()

I'm wondering if there is a much better way to do this?

Answer 1

Probably the best way to do this is to put the definition of x and y into function 2, and have them be inputs and outputs of function 1.

def func1(x, y):
    ##lots of code
    x+=1
    y+=1
    return x, y

def func2():
    x = 5
    y = 10
    while True:
        x, y = func1(x, y)

Other alternatives include defining x and y globally and using global x , global y or using mutable default arguments to make the function retain state, but generally better to not resort to these options if you don't have to.

Answer 2

x = None
y = None

def set1():
    global x, y
    x=5
    y=10

def func1():
    global x, y
    x+=1
    y+=1

def func2():
    while True:
        func1()
set1()
func2()

Answer 3

A bit of code review and recommendations:

def func1():
   def set1():
      x=5
      y=10
   ##lots of code
   x+=1
   y+=1

def func2():
   while True:
      func1()

set1() # This won't work because set1 is in the local scope of func1
       # and hidden from the global scope
func2()

Looks like you want the function to count each time it is called. May I suggest something like this?:

x=5
y=10

def func1():
    global x, y
    x+=1
    y+=1
    print x, y

def func2():
    while True:
        func1()

func2()

Better than using a global variable, stick them in a mutable object in a nested scope:

Counts = dict(x=5, y=10)

def func1():
    Counts['x'] += 1
    Counts['y'] += 1
    print Counts['x'], Counts['y']

def func2():
    while True:
        func1()

func2()

Answer 4

** just saw the edit on going up instead of down - modified code to suit**

It's hard to tell from your question what your actual use case is but I think a Python generator may be the right solution for you.

def generator(x, y):
    yield x,y
    x += 1
    y += 1

Then to use:

if __name__ == "__main__":
    my_gen = generator(10,5)

    for x,y in my_gen:
        print x,y
        if x+y > 666:
            break

This may be a slightly advanced for someone new to Python. You can read up on generators here: http://anandology.com/python-practice-book/iterators.html

Answer 5

First of all, the set1 function doesn't seem to do much at all, so you could take it away.

If you want to keep count of the number of calls or keep state between calls, the best, more readable way is to keep this inside an object:

class State(object):
    def __init__(self):
        self._call_count = 0
        self.x = 5

    def func1(self):
        self._call_count += 1
        self.x =  ... Whatever

def func2():
    state = State()
    while True:
        state.func1()