How to avoid converting an integer to string when concatenating
Question:
I know that in python, you can’t simply do this:
number = 1
print "hello number " + number
you have to do this:
print "hello number " + str(number)
otherwise you’ll get an error.
My question is then, being python such a compact language and this feature of automatic casting/converting from integer to string available in so many other languages, isn’t there away to avoid having to use the str() function everytime? Some obscure import, or simply another way to do it?
Edit: When I say another way, I mean simpler more compact way to write it. So, I wouldn’t really consider format and alternative for instance.
Thanks.
Answers:
You can avoid str():
print 'hello number {}'.format(number)
Anyway,
'abc' + 123
is equivalent to
'abc'.__add__(123)
and the __add__ method of strings accepts only strings.
Just like
123 + 'abc'
is equivalent to
(123).__add__('abc')
and the __add__ method of integers accept only numbers (int/float).
As this answer explains, this will not happen in Python because it is strongly typed. This means that Python will not convert types that you do not explicitly say to convert.
I tend to use the more compact format
>>> print "one",1,"two",2
one 1 two 2
Or, in python 3,
>>> print("one",1,"two",2)
one 1 two 2
Notice however that both options will always introduce a space between each argument, which makes it unsuitable for more complex output formatting, where you should use some of the other solutions presented.
I know that in python, you can’t simply do this:
number = 1
print "hello number " + number
you have to do this:
print "hello number " + str(number)
otherwise you’ll get an error.
My question is then, being python such a compact language and this feature of automatic casting/converting from integer to string available in so many other languages, isn’t there away to avoid having to use the str() function everytime? Some obscure import, or simply another way to do it?
Edit: When I say another way, I mean simpler more compact way to write it. So, I wouldn’t really consider format and alternative for instance.
Thanks.
You can avoid str():
print 'hello number {}'.format(number)
Anyway,
'abc' + 123
is equivalent to
'abc'.__add__(123)
and the __add__ method of strings accepts only strings.
Just like
123 + 'abc'
is equivalent to
(123).__add__('abc')
and the __add__ method of integers accept only numbers (int/float).
As this answer explains, this will not happen in Python because it is strongly typed. This means that Python will not convert types that you do not explicitly say to convert.
I tend to use the more compact format
>>> print "one",1,"two",2
one 1 two 2
Or, in python 3,
>>> print("one",1,"two",2)
one 1 two 2
Notice however that both options will always introduce a space between each argument, which makes it unsuitable for more complex output formatting, where you should use some of the other solutions presented.