Exactly. Kind of an own-goal too, from none other than ex-BDFL. While not totally obvious, it's not impossible to widen the syntax to allow multi-line lambdas, you just need to ditch the stack-based lexer-integrated whitespace sensitivity behaviour.

This works for conditionals:

    In [4]: f = lambda x: "Yes" if x else "No"

    In [5]: f(True)
    Out[5]: 'Yes'

    In [6]: f(False)
    Out[6]: 'No'

It's Python's version of ternary operators, so not sure if that counts as a "true" conditional; but it is one.

Loops don't work, but list comprehensions do, and they are definitely the way to go here. Multi-line loops deserve a `def`.

> Can only use expressions, not statements. E.g. `print`s, loops, conditionals are out.

print is a function (and thus can be used in expressions)

python has conditional expressions (<true-val> if <cond> else <false-val>)

loops are a limitation, though comprehensions, map(), functools.reduce(), and the itertools module can allow lots of looping functionality in an expression.

print() is a function now and you can use it with lambdas.

Even in Python 2, you can do something like this:

    println = lambda s: sys.stdout.write(s + '\n')

Not that it really makes things much better, but, at least it shows you can do it.

The lambda calculus is Turing complete, so in theory, Python’s lambdas should suffice...

Turing completeness is completely unrelated to whether or not anonymous functions are easy to use in Python.

Which of course says nothing about usability and readability.

I mean... You're right. They suffice. They're just less friendly (i.e. useful) than lambdas in other languages.