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How can I apply a list as a variable number of arguments to the python print built-in?

So you can apply a variable amount of arguments from a list to a normal function by doing this
someFunc(*[1,2,3])
But it doesn't work when I used the built-in print
print(*[1,2,3])
^
SyntaxError: invalid syntax
How can I achieve the same effect with print?

The issue is that in python prior to python 3, print is a keyword of the language and not a function, so it doesn't work the same way. If you want to achieve a similar effect you can just make your own print function
def output(*args):
print ' '.join(str(i) for i in args)
then use output(*[1,2,3])
Or if your version of python2 is recent enough (>= 2.6) you can do
from __future__ import print_function
to get the python 3 semantics.

Python 2.7.3 : Sep argument showing error

When I am using sep argument in the Python 2.7.3, it is showing error
for example:-
>>>print ("Hello","World",sep ="**")
File "<stdin>", line 1
print ("Hello","World",sep ="**")
^
SyntaxError: invalid syntax

In Python 2.x, unlike in Python 3.x, print is not a function, but a statement described here. Basically it means that print is treated as a keyword (like for) and is not as powerful as the print function that you know from Python 3.x. In particular, it does not support the sep keyword argument.
You can make print behave similarly to Python 3.x by using the following import:
from __future__ import print_function
If you prefer no to use this import, you can achieve the effect you wanted with:
print "**".join(["Hellow", "World"])

You need to type this line first:
from __future__ import print_function
To make print a function, and allow passing arguments like that.

print tuple as number of arguments

I want to pass the variadic number of arguments and then print them (if some conditions are true).
When I try to do so:
def my_print(*args)
print args
It prints a tuple. How do I make python act my_print(a,b) as print a,b ?

You could do this:
from __future__ import print_function
print(*args)
This gets you the 3.x style print function so you can unpack the arguments. Do note that you then need to use the 3.x syntax everywhere in that module, however.

In Python 2.x you can use str.join:
def my_print(*args):
print ' '.join(map(str, args))
If you are using Python 3.x then it's even easier because there's a print function:
def my_print(*args):
print(*args)
Other answers also mention that you can from __future__ import print_function, but this has the disadvantage that all your existing code that uses the print statement will break.

Use builtin print function:
from __future__ import print_function
my_print = print
Or
my_print = getattr(__builtins__, 'print')

You could try
for _ in len(range(args)):
print a[_],
But it looks like the other answers are more correct

is print a function in Python?

In python everything is an object and you can pass it around easily.
So I can do :
>> def b():
....print "b"
>> a = b
>> a()
b
But if I do
a = print
I get SyntaxError . Why so ?

In Python 2.x, print is a statement not a function. In 2.6+ you can enable it to be a function within a given module using from __future__ import print_function. In Python 3.x it is a function that can be passed around.

In python2, print is a statement. If you do from __future__ import print_function, you can do as you described. In python3, what you tried works without any imports, since print was made a function.
This is covered in PEP3105

The other answers are correct. print is a statement, not a function in python2.x. What you have will work on python3. The only thing that I have to add is that if you want something that will work on python2 and python3, you can pass around sys.stdout.write. This doesn't write a newline (unlike print) -- it acts like any other file object.

print is not a function in pre 3.x python. It doesn't even look like one, you don't need to call it by (params)

python's print function not exactly an ordinary function?

Environment: python 2.x
If print is a built-in function, why does it not behave like other functions ? What is so special about print ?
-----------start session--------------
>>> ord 'a'
Exception : invalid syntax
>>> ord('a')
97
>>> print 'a'
a
>>> print('a')
a
>>> ord
<built-in function ord>
>>> print
-----------finish session--------------

The short answer is that in Python 2, print is not a function but a statement.
In all versions of Python, almost everything is an object. All objects have a type. We can discover an object's type by applying the type function to the object.
Using the interpreter we can see that the builtin functions sum and ord are exactly that in Python's type system:
>>> type(sum)
<type 'builtin_function_or_method'>
>>> type(ord)
<type 'builtin_function_or_method'>
But the following expression is not even valid Python:
>>> type(print)
SyntaxError: invalid syntax
This is because the name print itself is a keyword, like if or return. Keywords are not objects.
The more complete answer is that print can be either a statement or a function depending on the context.
In Python 3, print is no longer a statement but a function.
In Python 2, you can replace the print statement in a module with the equivalent of Python 3's print function by including this statement at the top of the module:
from __future__ import print_function
This special import is available only in Python 2.6 and above.
Refer to the documentation links in my answer for a more complete explanation.

print in Python versions below 3, is not a function. There's a separate print statement which is part of the language grammar. print is not an identifier. It's a keyword.

The deal is that print is built-in function only starting from python 3 branch. Looks like you are using python2.
Check out:
print "foo"; # Works in python2, not in python3
print("foo"); # Works in python3

print is more treated like a keyword than a function in python. The parser "knows" the special syntax of print (no parenthesis around the argument) and how to deal with it. I think the Python creator wanted to keep the syntax simple by doing so. As maverik already mentioned, in python3 print is being called like any other function and a syntx error is being thrown if you do it the old way.