It's great for beginners. Then it turns into a mess.
- A huge ecosystem of good third-party libraries.
- Named arguments.
- Multiple inheritance.
- It's easy to learn and read. However, it's only easy to learn and read at the start. Once you get past "Hello world" Python can get really ugly and counterintuitive.
- The Pythonic philosophy that "There should be one -- and preferably only one -- obvious way to do it." As someone who loves working within rules and rigid frameworks, I love this philosophy! As someone who writes Python, I really wish Python actually stuck to this philosophy. See below.
- Forced indentation. Some love it because it enforces consistency and a degree of readability. Some hate it because they think it enforces the wrong consistency. To each their own.
- Dynamic typing. There are lots of dynamically-typed languages and lots of statically-typed languages. Which kind of typing is better isn't a Python debate, it's a general programming debate.
-
400 ways (more or less) to interpolate strings. This prints "Hello Robin!" 3 times:
user = {'name': "Robin"} print(f"Hello {user['name']}!") print("Hello {name}!".format(**user)) print("Hello %(name)s!" % user)
If there was a unique and obvious use-case for each of these then that would be one thing, but there's not.
-
69 top-level functions that you have to just memorize. GvR's explanation sounds nice, but in reality it makes things confusing.
-
map
doesn't return a list, even though the whole point of a mapping function is to create one list from another. Instead it returns amap
object, which is pretty much useless since it's missingappend
,reverse
, etc. So, you always have to wrap it inlist()
, or use a list comprehension, which, speaking of... -
List comprehensions are held up as an excellent recent-ish addition to Python. People say they're readable. That's true for simple examples (e.g.
[x**2 for x in range(10)]
) but horribly untrue for slightly more complex examples (e.g.[[row[i] for row in matrix] for i in range(4)]
). I chalk this up to... -
Weird ordering in ternary/one-line expressions. Most languages follow a consistent order where first you declare conditions, then you do stuff based the on those conditions:
if user.isSignedIn then user.greet else error
for user in signedInUsers do user.greet
Python does this in the opposite order:
user.greet if user.isSignedIn else error
[user.greet for user in signedInUsers]
This is fine for simple examples. It's bad for more complex logic because you have to first find the middle of the expression before you can really understand what you're reading.
-
Syntax for tuples. If you write a single-item tuple
(tuple,)
but forget the trailing comma, it's no longer a tuple but an expression. This is a really easy mistake to make. Considering the only difference between tuples and lists is mutability, it would make much more sense to use the same syntax[syntax]
as lists, which does not require a trailing comma, and add afreeze
orimmutable
method. Speaking of... -
There's no way to make
dict
s or complex objects immutable. -
Regular expressions require a lot of boilerplate:
re.compile(r"regex", re.I | re.M)
Compared to JavaScript or Ruby:
/regex/ig
-
The goofy string literal syntaxes:
f''
,u''
,b''
,r''
. -
The many "magic" __double-underscore__ attributes that you just have to memorize.
-
You can't reliably catch all errors and their messages in one statement. Instead you have to use something like
sys.exc_info()[0]
. You shouldn't have a catch-all in production of course, but in development it's very useful, so this unintuitive extra step is annoying.
Most programmers will acknowledge criticisms of their favorite language. Instead, Pythonists will say, "You just don't understand Python."
Most programmers will say a piece of code is bad if it's inefficient or hard to read. Pythonists will say a piece of code is bad if "it isn't Pythonic enough." This is about as helpful as someone saying your taste in music is bad because "it isn't cultured enough."
Pythonists have a bit of a superiority complex.
That's like saying a "keep off the grass" sign prevents people from standing on the grass.
It's not really prevention if you're relying on people to self-censor and there's absolutely no obstacle standing in their way. Might as well leave your house and car doors unlocked while you're at it.
That doesn't help if they aren't aware of the convention in the first place.
If they aren't aware then there's nothing to stop them making the mistake.
In a compiled language with a proper 'privacy' mechanism the compiler would prevent the program from compiling and tell the programmer what they've done wrong. They'd either read the error and understand the problem or do further investigation and learn about the privacy mechanism, and then they'd fix their code.
In Python their code would run unimpeded with no warning about the mistake they'd just made, and then it would potentially break later down the line when they update their libraries and find that private variable is now missing because the implementation has been changed.
It need not even be an inexperienced programmer, it might just be a tired, overworked programmer who works on several language and forgot Python's convention because they work with so many different languages and it's hard to remember every language's little foibles. An enforcement mechanism would save them a headache.
Obviously Python isn't compiled in the conventional sense and its dynamic nature would mean any kind of actual enforcement would incur some runtime overhead, so I don't begrudge the fact they chose for forgo enforcement in favour of performance, but the point stands that a naming convention is not the 'perfect' solution.
Even if it were a 'perfect' solution, such conventions are not unique to Python.
Other languages have their own sets of conventions, but the problem is that there will always be groups who opt to break convention because they want to follow their own conventions, thus multiple different competing conventions appear.
Take C++ for example: one older convention is to prefix private member variables with
m_
, Google's style guide says to use an underscore suffix, some people use a preceding underscore like Python does, while other people (myself included) don't give private members a special naming convention at all and just rely entirely on the privacy mechanism.<sarcasm>How very inclusive.</sarcasm>