Python

没有Django for Python 3。 静态类型。是的，动态类型是很棒的东西，但有时我确实想让它成为静态的。 正确的unicode支持(在Python 3中修复) Construtors命名。我讨厌代码中的所有这些下划线。 线程的效率不是很高

计划

缺少静态类型 没有静态函数重载(由于上述原因)导致字段访问器的名称很长 没有统一的对象系统 有点慢 相对较小的社区

C#

Lack of multiple dispatch based on the runtime type of the method arguments. dynamic should solve most of this, but it hasn't been released yet. Interface implementation is declarative not structural. I really like the way Google's Go language is doing types Making asynchronous method calls is really bulky (and I'm pretty sure all threads are OS threads, not lightweight threads) No macro system. I'm not talking about C-style macros here; I'm talking LISP/Scheme style macros Operators are static methods and their signatures are overly constrained (and you can't create new ones).

Python:

速度 静态分析(缺乏) 匿名函数仅限于一个表达式

我讨厌Java(目前它是我最喜欢的语言)的五个方面，排名不分先后。

As much as I am a fan of Java Generics, there are a lot of oddities that arise from the way it was designed. As such there a myriad of annoying limitations with generics (some of which are the result of type-erasure). The way Object.clone() and the Cloneable interfaces work is totally broken. Instead of taking the high-road and making everything an object (a.la. SmallTalk), Sun wimped out created two distinct categories of data-types: Objects and primitives. As a result there are now two representations for fundamental data types and wierd curiosities such as boxing/unboxing and not being able to put primitives in a Collection. Swing is too complex. Don't get me wrong: there's a lot of cool stuff one can do with Swing but it is a great example of over-engineering. This final complaint is equally the fault of Sun and those whom have written XML libraries for Java. Java XML libraries are way too complicated. In order to simply read in an XML file, I often have to worry about what parser I am using: DOM or SAX? The APIs for each is equally confusing. Native support in the language for easily parsing/writing XML would be very nice. java.util.Date sucks. Not only is it unnecessarily complicated but all the useful methods have been deprecated (and replaced with others that increase complexity).

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.