Python:

我仍然是python的一般用户，所以我的抱怨可能只是知识的锁或误用。欢迎提出意见。我很喜欢这门语言。

Poor thread support and GIL. If you'd like to take use of multicore platform, most of the python programmers would probably recommend multiprocessing or some sort, don't use threading. It wouldn't give you the performance you are expecting. property only for instance variable. _class_var = property(classmethod(some_method)) just wouldn't work. How can I get a property wrapped class variable? no access control. All access controls are syntax mangling. Like private is __private, protect is _protected, etc... And hope that everyone programs python follows the naming convention. Come on, we can do better than that. I agree the python philosophy of being simple and clear syntax but some simple and clear syntax not being supported seems lock of good judgement, in my opinion. Such as, a++, ++a, a-- and --a, self-de/increment, what's wrong with those? foo = (a > b ? a : b) unary operation, what's wrong with those? (I know py2.6 has something similar introduced, but given the massive support of almost every other language for those simple syntax, why reinventing the wheel? why not just follow the best practice? Shouldn't a good thing just keep in its good "form"?) Program to interface. Python has no interface or abstract class concept (py3k has something called abc), everything is concrete. Providing an "interface" or "abstract" keyword to build class skeleton and guard class inheritance and extension wouldn't be a bad idea I think. It helps on top-down design. Currently, I just have to fill the each of methods with NotImplementedError, quite a tedious job. I have to add this. version less than 3.x has str and unicode types. This is a true nightmare. It makes ascii and non-ascii/unicode mixing most likely to fail (bad, bad)

我看到人们抱怨速度。我不明白。它是一种解释语言，代码直到运行时才编译成机器代码，这就是它的本质。你不能比较解释语言和编译语言的速度。据我所知，在解释/脚本语言中，python并不慢。

C#

I wish I could switch() on any type, and that case could be any expression. Can't use object initializer syntax with 'readonly' fields / private set autoprops. Generally, I want language help with making immutable types. Use of {} for namespace and class and method and property/indexer blocks and multi-statement blocks and array initializers. Makes it hard to figure out where you are when they're far apart or mismatched. I hate writing (from x in y ... select).Z(). I don't want to have to fall back to method call syntax because the query syntax is missing something. I want a do clause on query syntax, which is like foreach. But it's not really a query then.

我真的到达这里了。我认为c#非常棒，而且很难发现它有什么缺陷。

Python:

缺少静态类型 默认参数处理(特别是可以为未来的调用者更改默认参数的事实!) 需要的下划线太多(构造函数必须调用__init__) 缺少适当的私有成员和函数(惯例只是说大多数以下划线开头的东西都是私有的，除了像__getattr__这样的东西不是) 有趣的打印到文件的语法(但他们在Python 3中修复了这个问题)

JavaScript:

The Object prototype can be modified. Every single object in your program gets new properties, and something probably breaks. All objects are hash maps, but it's difficult to safely use them as such. In particular, if one of your keys happens to be __proto__, you're in trouble. No object closure at function reference time. In fact, no object closure at all -- instead, this is set whenever a function is called with object notation or the new operator. Results in much confusion, particularly when creating event callbacks, because this isn't set to what the programmer expects. Corollary: calling a function without object notation or the new operator results in this being set equal to the global object, resulting in much breakage. Addition operator overloaded to also perform string concatenation, despite the two operations being fundamentally different. Results in pain when a value you expect to be a number is in fact a string. == and != operators perform type coercion. Comparisons between different types involve a list of rules that no mortal can remember in full. This is mitigated by the existence of === and !== operators. Both null and undefined exist, with subtly different, yet redundant meanings. Why? Weird syntax for setting up prototype chains. parseInt(s) expects a C-style number, so treats values with leading zeroes as octal, etc. You can at least parseInt(s, 10) but the default behaviour is confusing. No block scope. Can declare the same variable more than once. Can use a variable without declaring it, in which case it's global and probably breaks your program. with { }. Really difficult to document with JavaDoc like tools.

JavaFX

Type inference sometimes doesn't behave like you would expect, so you often need to explicitly declare the type. def behaves likes const in C and not final in Java you can insert a value in a sequence by accessing an index >= seq.length, which should actually throw a compiler error (according to the reference). if you assign null to a String, it defaults to "". If you assign null to an Integer, a compiler error is thrown (in contrast to what the reference says). handles CheckedExceptions the same way as RuntimeExceptions

我刚刚发现，在c#中创建泛型方法时，我不能使用Enum作为类型约束。

微软有一个足够好的解释，但仍然。我疯了

public static T MyFunc<T>(string arg) where T:Enum //wont work :(