Python: why doesn't my string return or print when I run my code

Question

def the_flying_circus(Question = raw_input("Do you like the Flying Circus?")):
 if Question == 'yes':
 print "That's great!" 
 elif Question == 'no':
 print "That's too bad!"

I am trying to get the if expression to run the code and return either string based on the raw input. Everytime I run it, the question prompts but then when I attempt to input 'yes or no' it gives me this error:

 Traceback (most recent call last):
 File "C:\Users\ftidocreview\Desktop\ex.py", line 1, in <module>
 def the_flying_circus(Question = input("Do you like the Flying Circus?")):
 File "<string>", line 1, in <module>
NameError: name 'yes' is not defined
>>> 

• roippi: You're not running the same code you gave.
• DSM: @MxyL: yes, really. Compare the raw_input in the first line of the code to the input in the traceback.

Answer 1

You should use raw_input() instead of input() otherwise Python interprets the user input as variables (that's why you're getting name 'yes' is not defined).

Furthermore, you shouldn't use raw_input() as default parameter value as this is evaluated whenever Python loads the module.

Consider the following:

def the_flying_circus(Question=None):
 if Question is None:
 Question = raw_input("Do you like the Flying Circus?")
 if Question == 'yes':
 print "That's great!" 
 elif Question == 'no':
 print "That's too bad!"

Although, I have to say, it's not entirely clear what purpose the above function has because Question can now be both a question and the user's answer. How about passing in the question as a string and assigning the result to Answer?

def the_flying_circus(Question):
 Answer = raw_input(Question)
 if Answer == 'yes':
 print "That's great!" 
 elif Answer == 'no':
 print "That's too bad!"

Lastly, variable names in Python are written without capitals at the beginning so the code would become:

def the_flying_circus(question):
 answer = raw_input(question)
 if answer == 'yes':
 print "That's great!" 
 elif answer == 'no':
 print "That's too bad!"

• Cvrpapc: I SEE! Thank you so much. Pass Question as a str and assign the result to answer. That's sorta what I wanted to do but I just didn't conceptualize it right. Total noob.
• smci: if not Question is preferred idiom to if Question is None
• smci: and the variable should be named question to be PEP-8 compliant
• Simeon Visser: @smci: if not Question and if Question is None are not equivalent so you can't always use either of them. Also, I adapted the code as written in the question - it's not always useful to teach people about additional stuff, such as PEP8, when you're starting to learn Python.