i want to print all the values using the command line please

Question

I'm very new to programming so please help me with this!

I wish to print all the values of roman_numeral_map in the command line, but I get lots of errors.

Here is my code:

class roman1:

    roman_numeral_map = (('M',  1000),
                     ('CM', 900),
                     ('D',  500),
                     ('CD', 400),
                     ('C',  100),
                     ('XC', 90),
                     ('L',  50),
                     ('XL', 40),
                     ('X',  10),
                     ('IX', 9),
                     ('V',  5),
                     ('IV', 4),
                     ('I',  1))

    def to_roman():
        '''convert integer to roman numeral'''
        for numeral, integer in roman_numeral_map:
            print(numeral, integer)


    if __name__ == '__main__':
        self.roman = roman1()
        roman.to_roman

UPDATE:

This is the traceback I get (thanks)!

Traceback (most recent call last):
  File "/Users/michaelmatos/PycharmProjects/diveintopython3/roman1.py", line 4, in <module>
    class roman1:
  File "/Users/michaelmatos/PycharmProjects/diveintopython3/roman1.py", line 27, in roman1
    self.roman = roman1()
NameError: name 'roman1' is not defined

Please correct your indentation and post the full traceback. — Tim, Nov 22 '13 at 01:16
Your problem doesn't appear to be in your print... but in other syntax. What data type is roman_numeral_map supposed to be? — Isaiah Taylor, Nov 22 '13 at 01:16

score 3 · Accepted Answer · edited May 23 '17 at 12:05

You have a few issues with your code, I've fixed them below with comments inline.

Importantly, leading whitespace is significant in Python and you need to use self to reference instance variables and methods.

class roman1:
    roman_numeral_map = (('M',  1000),
                         ('CM', 900),
                         ('D',  500),
                         ('CD', 400),
                         ('C',  100),
                         ('XC', 90),
                         ('L',  50),
                         ('XL', 40),
                         ('X',  10),
                         ('IX', 9),
                         ('V',  5),
                         ('IV', 4),
                         ('I',  1))

    def to_roman(self): # Instance methods take `self`
        '''convert integer to roman numeral'''
        for numeral, integer in self.roman_numeral_map: # Note: `self`
            print(numeral, integer)


if __name__ == '__main__': # Note: Indent to same level as `class` above
    roman = roman1() # `roman` is global, no need for `self`
    roman.to_roman() # Use `()` to *call* `to_roman()`

See it run!

thank you very much man!!! i really appreciate the sense of community of this industry — matos416, Nov 22 '13 at 01:38

Jesus Noland · Answer 2 · 2013-11-22T01:27:52.050

If you are just looking to iterate through the tuple and print out each selection than you can try this.

>>> i = 0
>>> while i < len(m):
...     print m[i]
...     i += 1
... 
('M', 1000)
('CM', 900)
('D', 500)
('CD', 400)
('C', 100)
('XC', 90)
('L', 50)
('XL', 40)
('X', 10)
('IX', 9)
('V', 5)
('IV', 4)
('I', 1)

It would be great to see an example of your desired output.

Declare your class like so just to get started.

class roman1:
    pass

Then instantiate an instance of roman1 class.

roman = roman1()

Timidger · Answer 3 · 2013-11-22T01:34:58.983

The error message occurs because the if block is IN the class deceleration. 'roman1' has not been made yet. Also, you should declare an attribute of the class (self.roman) in the constructor, which is a method named __init__

class roman1:
    def __init__():
        self.roman = self

Though in this case, it is useless and redundant. If you want to make the roman variable outside of the class, omit the 'self' part

Assuming your data structure is correct (Nested tuples to create essentially a table with two columns), you can print each grouping with this:

for group in roman_numeral_map:
    print group

To print each value, use a nested for loop:

for group in roman_numeral_map:
    for value in group:
        print value

score 0 · Answer 4 · answered Nov 22 '13 at 01:31

An altered class:

class RomanNumeral():
    values = [
        ('M', 1000),
        ('CM', 900),
        ('D',  500),
        ('CD', 400),
        ('C',  100),
        ('XC', 90),
        ('L',  50),
        ('XL', 40),
        ('X',  10),
        ('IX', 9),
        ('V',  5),
        ('IV', 4),
        ('I',  1)
    ]

    def __init__(self, i):
        self.i = i

    def __str__(self):
        num = []
        n = self.i
        for ch,val in RomanNumeral.values:
            while n >= val:
                num.append(ch)
                n -= val
        return ''.join(num)

if __name__ == '__main__':
    print(RomanNumeral(4))

i want to print all the values using the command line please

UPDATE:

4 Answers4