lambda functions

[Pierre]

Hello,

I would like to know if it is possible to define a loop in a lambda
function....

How to manage the indents ? Example :
s_minus_1 = lambda s : for index in range(0, len(s)) : s[index] = s
[index]-1


Thanks !

 

[Chris Rebert]

Hello,

I would like to know if it is possible to define a loop in a lambda
function....

Not possible. Lambdas can only contain a single expression. A loop is
a block statement.
Just use a named function instead. There's nothing that can be done
with a lambda that can't be done with a named function instead.

Cheers,
Chris

 

[Javier Collado]

Hello,

This page has some advice about how to avoid some of the lambda
functions limitations:
http://p-nand-q.com/python/stupid_lambda_tricks.html

In particular, it suggests to use map function instead of for loops.

Best regards,
Javier

 

[Gabriel Genellina]

I would like to know if it is possible to define a loop in a lambda
function....

How to manage the indents ? Example :
s_minus_1 = lambda s : for index in range(0, len(s)) : s[index] = s
[index]-1

You can't. lambda is just a way to define a short, inline, anonymous
function, and its body can only contain expressions, not statements.

Even if what you want were legal, giving a name to the resulting
expression kind of defeats the purpose of lambda - use a normal function
instead:

def s_minus_1(s):
"document usage here"
for index,item in enumerate(s):
s[index] -= 1

 

[Paul Rubin]

s_minus_1 = lambda s : for index in range(0, len(s)) : s[index] = s
[index]-1

What are you trying to do here anyway? That looks broken.
Maybe you want the list.insert method.