Question

Fairly simple question, I imagine…I have literally just installed Python and am testing some of the beginner tutorials.

I wanted to create a menu that allows you to add items to a list, then check to see if theyre added: testing functions, and lists in the process.

#create empty list and define variables
firstlist = {'joe'}
additem = "test"
printthis = "test"

#create menu, add or check name
def menu():
    #print what options you have
    print "Add to list: type '1'"
    print "Check for name: type '2'"
    print "To exit program: type '3'"
    return input ("Choose your option: ")

def addmenu():
    additem = input("Name of list item: ")
    firstlist.append(additem)
    print additem, "has been appended"

def checkmenu():
    printthis = input ("What are you looking for?: ")
    if firstlist.has_key(printthis):
        print "is in the list"
    else:
        print "is not in the list"

# Perform action
loop = 1
choice = 0
while loop == 1:
    choice = menu()
    if choice == 1:
        addmenu()
    elif choice == 2:
        checkmenu()
    elif choice == 3:
        loop = 0
    elif choice > 3:
        print "You made an incorrect selection"

Heres my error:

Traceback (most recent call last):
  File "C:\Python27\testing python\tutorials\dictionaryselection", line 32, in <module>
    addmenu()
  File "C:\Python27\testing python\tutorials\dictionaryselection", line 15, in addmenu
    additem = input("Name of list item: ")
  File "<string>", line 1, in <module>
NameError: name 'TESTING' is not defined

Not sure whats going on…Any help would be appreciated.

Working code below: converted to python 3.x

#create empty list and define variables
firstlist = ['Joe']
additem = "test"
printthis = "test"

#create menu, add or check name
def menu():
    #print what options you have
    print ("")
    print ("Add to list: type '1'")
    print ("Check for name: type '2'")
    print ("To list the whole list '3'")
    print ("To exit program: type '4'")
    print ("-------------------------")
    return input ("Choose your option: ")

def addmenu():
    additem = input("Name of list item: ")
    firstlist.append(additem)
    print (additem, "has been appended")

def checkmenu():
    printthis = input("What are you looking for?: ")
    if printthis in firstlist:
        print ("is in the list")
    else:
        print ("is not in the list")

def listlist():
    print (firstlist[1])

# Perform action
loop = 1
choice = 0
while loop == 1:
    choice = int(menu())
    if choice == 1:
        addmenu()
    elif choice == 2:
        checkmenu()
    elif choice == 3:
        listlist()
    elif choice == 4:
        loop = 0
    elif (choice > 4):
        print ("You made an incoorect selection")

Answer 1

There are multiple errors in the example, let us go through them. First, if you want a list then you need to define it as such, i.e.:

l = ['joe'] # this is a list
s = {'joe'} # this is a set

Now, since you are using Python 2, it is always recommended to use raw_input in place of input. The later will apply eval on the obtained string, so it will evaluate the input as Python code. You generally don’t want that for security reasons (I know this is an example). So, let’s change every input to raw_input. The problem now is that entering a string that represents a number while using eval, actually converts the string to a number. Now you need to do the same, but using raw_input. Since your options are limited to integer values, the solution is int(raw_input()).

The third problem is related to has_key. If the object used is a set or a list, then there is no such method has_key defined for them. That would work if the object in question were a dict, but it is not. The proper way to check for containment in the given code is something in A. Doing this while using set is much more efficient than while using list, and the code remains the same (except you need to change append to add).

Can you adjust your code now ?