passing variable arguments in python

What you want is default arguments. This allows your function to be called by passing only a part of its parameters, and defaults the other to a pre-defined value.

For instance:

def createValues(value1=12, value2=27, value3=42):
 value = dict()
 value["VALUE1"] = value1
 value["VALUE2"] = value2
 value["VALUE3"] = value3
 print (value["VALUE1"],value["VALUE1"],value["VALUE1"])

will allow you to call your function by either of the following ways:

>>> createValues(1, 2, 3)
1, 2, 3
>>> createValues()
12, 27, 42
>>> createValues(value2=1)
12, 1, 42
>>> createValues(0, 5)
0, 5, 42

Since you seem confused with the * unary operator, I suggest that you read a bit about arguments unpacking (for example, check this post).

Besides, using two commas as in createValues(2000,,1) is in no way a valid syntax in Python.

From my beginners point of view, I see two ways :

Using lists

The arg of createValues become a list so you have as many values as you want.

def createValues(values):
 value = dict()
 #Inserting
 for val in iter(values):
 index = str(values.index(val))
 value["VALUE"+index] = val
 #Printing
 for (key, value) in value.iteritems(): 
 print ("Key : " + key + " | Value : " + value)
createValues([2000,21000001,1])
createValues([2000,1])

Using default value

3 args for your specific case

def createValues(value1, value3, value2 = None):
 value = dict()
 value["VALUE1"] = value1
 if value2 is not None:
 value["VALUE2"] = value2
 value["VALUE3"] = value3
 print (value["VALUE1"],value["VALUE1"],value["VALUE1"])
createValues(2000,21000001,1)
createValues(value1 = 2000, value3 = 1)

You cannot call a function like this:

createValues(2000,,1)

You can however check if the argument is None and work with that.

def createValues(value1, value2, value3):
 value = dict()
 value["VALUE1"] = value1 or 0
 value["VALUE2"] = value2 or 0
 value["VALUE3"] = value3 or 0
 print (value["VALUE1"],value["VALUE1"],value["VALUE1"])

Now, you can use the function like this:

createValues(2000, None, 1)

I have used the default value 0 for any missing argument.

Also, the arguments are not being converted into a tuple. You are packing the arguments into a tuple when printing. Try this instead (note the lack of parenthesis):

print value["VALUE1"], value["VALUE1"], value["VALUE1"]

• python
• function