Isn't that literally a core principal of Python? They enforce all kind of coding styles within the language, not the mention all the PEPs.

But PEPs are not enforced in the language level. Also there are cases where there could fit two simple expression in a lambda. Also the language still doesn't stop you from abusing lambdas, you can nest them. It could be stated in one of the PEPs that "no overly complicated lambdas" and that's it, there is no need for the language to enforce this.

PEPs are literally the language, in my opinion. It may not be enforced on an implementation level, but some have been. You can't mix spaces and tabs now. That seems like a style choice being enforced on every level.

While I see the use for multi-statement lambdas, and I use them all the time in {Java,Coffee}Script, they are rarely needed in Python as there is always a more idiomatic way to write the code. In particular, with for loops and generator expressions (~list comprehensions) you can cover almost all uses of .each, .map, .filter, .some (`any` in Python), .every (`all` in Python), etc.

That also dramatically reduces the value of lambdas. Without that limitation then they work as anonymous blocks of any complexity.