Return outside function python ошибка

Compiler showed:

File "temp.py", line 56
    return result
SyntaxError: 'return' outside function

Where was I wrong?

class Complex (object):
    def __init__(self, realPart, imagPart):
        self.realPart = realPart
        self.imagPart = imagPart            

    def __str__(self):
        if type(self.realPart) == int and type(self.imagPart) == int:
            if self.imagPart >=0:
                return '%d+%di'%(self.realPart, self.imagPart)
            elif self.imagPart <0:
                return '%d%di'%(self.realPart, self.imagPart)   
    else:
        if self.imagPart >=0:
                return '%f+%fi'%(self.realPart, self.imagPart)
            elif self.imagPart <0:
                return '%f%fi'%(self.realPart, self.imagPart)

        def __div__(self, other):
            r1 = self.realPart
            i1 = self.imagPart
            r2 = other.realPart
            i2 = other.imagPart
            resultR = float(float(r1*r2+i1*i2)/float(r2*r2+i2*i2))
            resultI = float(float(r2*i1-r1*i2)/float(r2*r2+i2*i2))
            result = Complex(resultR, resultI)
            return result

c1 = Complex(2,3)
c2 = Complex(1,4)
print c1/c2

What about this?

class Complex (object):
    def __init__(self, realPart, imagPart):
        self.realPart = realPart
        self.imagPart = imagPart            

    def __str__(self):
        if type(self.realPart) == int and type(self.imagPart) == int:
            if self.imagPart >=0:
                return '%d+%di'%(self.realPart, self.imagPart)
            elif self.imagPart <0:
                return '%d%di'%(self.realPart, self.imagPart)
        else:
            if self.imagPart >=0:
                return '%f+%fi'%(self.realPart, self.imagPart)
            elif self.imagPart <0:
                return '%f%fi'%(self.realPart, self.imagPart)

    def __div__(self, other):
        r1 = self.realPart
        i1 = self.imagPart
        r2 = other.realPart
        i2 = other.imagPart
        resultR = float(float(r1*r2+i1*i2)/float(r2*r2+i2*i2))
        resultI = float(float(r2*i1-r1*i2)/float(r2*r2+i2*i2))
        result = Complex(resultR, resultI)
        return result

c1 = Complex(2,3)
c2 = Complex(1,4)
print c1/c2

In Python, the return keyword ends the execution flow of a function and sends the result value to the main program. You must define the return statement inside the function where the code block ends. If you define the return statement outside the function block, you will raise the error “SyntaxError: ‘return’ outside function”.

This tutorial will go through the error in more detail, and we will go through an example scenario to solve it.

SyntaxError: ‘return’ outside function

What is a Syntax Error in Python?

Syntax refers to the arrangement of letters and symbols in code. A Syntax error means you have misplaced a symbol or a letter somewhere in the code. Let’s look at an example of a syntax error:

number = 45

print()number

    print()number
           ^
SyntaxError: invalid syntax

The ^ indicates the precise source of the error. In this case, we have put the number variable outside of the parentheses for the print function,

print(number)

45

The number needs to be inside parentheses to print correctly.

What is a Return Statement?

We use a return statement to end the execution of a function call and return the value of the expression following the return keyword to the caller. It is the final line of code in our function. If you do not specify an expression following return, the function will return None. You cannot use return statements outside the function you want to call. Similar to the return statement, the break statement cannot be outside of a loop. If you put a break statement outside of a loop you will raise “SyntaxError: ‘break’ outside loop“. Let’s look at an example of incorrect use of the return statement.

Example: Return Statement Outside of Function

We will write a program that converts a temperature from Celsius to Fahrenheit and returns these values to us. To start, let’s define a function that does the temperature conversion.

# Function to convert temperature from Celsius to Fahrenheit

def temp_converter(temp_c):

    temp_f = (temp_c * 9 / 5) + 32

return temp_f

The function uses the Celsius to Fahrenheit conversion formula and returns the value. Now that we have written the function we can call it in the main program. We can use the input() function to ask the user to give us temperature data in Celsius.

temperature_in_celsius = float(input("Enter temperature in Celsius"))

temperature_in_fahrenheit = temp_converter(temperature_in_celsius)

Next, we will print the temperature_in_fahrenheit value to console

print(<meta charset="utf-8">temperature_in_fahrenheit)

Let’s see what happens when we try to run the code:

    return temp_f
    ^
SyntaxError: 'return' outside function

The code failed because we have specified a return statement outside of the function temp_converter.

Solution

To solve this error, we have to indent our return statement so that it is within the function. If we do not use the correct indentation, the Python interpreter will see the return statement outside the function. Let’s see the change in the revised code:

# Function to convert temperature from Celsius to Fahrenheit

def temp_converter(temp_c):

    temp_f = (temp_c * 9 / 5) + 32

    return temp_f

temperature_in_celsius = float(input("Enter temperature in Celsius"))

temperature_in_fahrenheit = temp_converter(temperature_in_celsius)

print(temperature_in_fahrenheit)

Enter temperature in Celsius10

50.0

The program successfully converts 10 degrees Celsius to 50 degrees Fahrenheit.

For further reading on using indentation correctly in Python, go to the article: How to Solve Python IndentationError: unindent does not match any outer indentation level.

Summary

Congratulations on reading to the end of this tutorial! The error: “SyntaxError: ‘return’ outside function” occurs when you specify a return statement outside of a function. To solve this error, ensure all of your return statements are indented to appear inside the function as the last line instead of outside of the function.

Here is some other SyntaxErrors that you may encounter:

• SyntaxError: unexpected character after line continuation character
• SyntaxError: can’t assign to function call

Go to the online courses page on Python to learn more about Python for data science and machine learning.

🚫 SyntaxError: ‘return’ outside function

This post was originally published on decodingweb.dev as part of the Python Syntax Errors series.

Python raises the error “SyntaxError: ‘return’ outside function” once it encounters a return statement outside a function.

Here’s what the error looks like:

File /dwd/sandbox/test.py, line 4
  return True
  ^^^^^^^^^^^
SyntaxError: 'return' outside function

Based on Python’s syntax & semantics a return statement may only be used in a function — to return a value to the caller.

However, if — for some reason — a return statement isn’t nested in a function, Python’s interpreter raises the «SyntaxError: ‘return’ outside function» error.

Using the return statement outside a function isn’t something you’d do on purpose, though; This error usually happens when the indentation-level of a return statement isn’t consistent with the rest of the function.

Additionally, it can occur when you accidentally use a return statement to break out of a loop (rather than using the break statement)

How to fix SyntaxError: ‘return’ outside function

This SyntaxError happens under various scenarios:

1. Inconsistent indentation
2. Using the return statement to break out of a loop
3. Let’s explore each scenario with some examples.

1. Inconsistent indentation: A common cause of this syntax error is an inconsistent indentation, meaning Python doesn’t consider the return statement a part of a function because its indentation level is different.

In the following example, we have a function that accepts a number and checks if it’s an even number:

def isEven(value):
  remainder = value % 2

  # if the remainder of the division is zero, it's even
return remainder == 0

As you probably noticed, we hadn’t indented the return statement relative to the isEven() function.

To fix it, we correct the indentation like so:

# ✅ Correct
def isEven(value):
  remainder = value % 2

  # if the remainder of the division is zero, it's even
  return remainder == 0

Problem solved!

Let’s see another example:

def check_age(age):
  print('checking the rating...')

# if the user is under 12, don't play the movie
if (age < 12):
  print('The movie can't be played!')
  return

In the above code, the if block has the same indentation level as the top-level code. As a result, the return statement is considered outside the function.

To fix the error, we bring the whole if block to the same indentation level as the function.

# ✅ Correct
def check_age(age):
  print('checking the rating...')

  # if the user is under 12, don't play the movie
  if (age < 12):
    print('The movie can't be played!')
    return

  print('Playing the movie')

check_age(25)
# output: Playing the movie

Using the return statement to break out of a loop: Another reason for this error is using a return statement to stop a for loop located in the top-level code.

The following code is supposed to print the first fifteen items of a range object:

items = range(1, 100)

# print the first 15 items
for i in items:
  if i > 15:
    return
  print(i)

However, based on Python’s semantics, the return statement isn’t used to break out of functions — You should use the break statement instead:

# ✅ Correct
items = range(1, 100)

# print the first 15 items
for i in items:
  if i > 15:
    break
  print(i)

And that’s how you’d fix the error «SyntaxError: ‘return’ outside function» in Python.

In conclusion, always make sure the return statement is indented relative to its surrounding function. Or if you’re using it to break out of a loop, replace it with a break statement.

Alright, I think it does it. I hope this quick guide helped you solve your problem.

Thanks for reading.

A return statement sends a value from a function to a main program. If you specify a return statement outside of a function, you’ll encounter the “SyntaxError: ‘return’ outside function” error.

In this guide, we explore what the “‘return’ outside function” error means and why it is raised. We’ll walk through an example of this error so you can figure out how to solve it in your program.

SyntaxError: ‘return’ outside function

Return statements can only be included in a function. This is because return statements send values from a function to a main program. Without a function from which to send values, a return statement would have no clear purpose.

Return statements come at the end of a block of code in a function. Consider the following example:

def add_two_numbers(x, y):
	answer = x + y
	return answer

Our return statement is the final line of code in our function. A return statement may be used in an if statement to specify multiple potential values that a function could return.

An Example Scenario

We’re going to write a program that calculates whether a student has passed or failed a computing test. To start, let’s define a function that checks whether a student has passed or failed. The pass-fail boundary for the test is 50 marks.

def check_if_passed(grade):
	if grade > 50:
		print("Checked")
		return True
	else: 
		print("Checked")
return False

Our function can return two values: True or False. If a student’s grade is over 50 (above the pass-fail boundary), the value True is returned to our program. Otherwise, the value False is returned. Our program prints the value “Checked” no matter what the outcome of our if statement is so that we can be sure a grade has been checked.

Now that we have written this function, we can call it in our main program. First, we need to ask the user for the name of the student whose grade the program should check, and for the grade that student earned. We can do this using an input() statement:

name = input("Enter the student's name: ")
grade = int(input("Enter the student's grade: "))

The value of “grade” is converted to an integer so we can compare it with the value 50 in our function. Let’s call our function to check if a student has passed their computing test:

has_passed = check_if_passed(grade)
if has_passed == True:
	print("{} passed their test with a grade of {}.".format(name, grade))
else:
	print("{} failed their test with a grade of {}.".format(name, grade))

We call the check_if_passed() function to determine whether a student has passed their test. If the student passed their test, a message is printed to the console telling us they passed; otherwise, we are informed the student failed their test.

Let’s run our code to see if it works:

  File "test.py", line 6
	return False
	^
SyntaxError: 'return' outside function

An error is returned.

The Solution

We have specified a return statement outside of a function. Let’s go back to our check_if_passed() function. If we look at the last line of code, we can see that our last return statement is not properly indented.

…
	else: 
		print("Checked")
return False

The statement that returns False appears after our function, rather than at the end of our function. We can fix this error by intending our return statement to the correct level:

	else: 
		print("Checked")
return False

The return statement is now part of our function. It will return the value False if a student’s grade is not over 50. Let’s run our program again:

Enter the student's name: Lisa
Enter the student's grade: 84
Checked
Lisa passed their test with a grade of 84.

Our program successfully calculates that a student passed their test.

Conclusion

The “SyntaxError: ‘return’ outside function” error is raised when you specify a return statement outside of a function. To solve this error, make sure all of your return statements are properly indented and appear inside a function instead of after a function.

Now you have the knowledge you need to fix this error like an expert Python programmer!