https://xkcd.com/792/

Both 2.7 and 3.6 documentation clearly state that you can't have multiple statements in a lambda function definition:
https://docs.python.org/2/refe...
https://docs.python.org/3/refe...

In fact the function body part of the lambda is not a statement at all, but a single expression that becomes the function's return value:
https://docs.python.org/3/refe...

The bug is foremost a flaw in the Interface call.
The spec can be described as "Here is a bit of data, send it back to me so I know you are alive".
But there are two separate sources for the length of the data:
- The write length
- The read length
Why a parameter for the read length at all?
We already know how long the string is!
.
The general rule is to have one authoritative source for any given peace of information.

While your sad "outsource you in a heartbeat" is sometimes true, your "almost half of the IT outsourcing contracts are canceled do to non-performance" needs to be compared to the fact that almost half of the large IT projects done in-house are canceled.