Tagged Questions
1
vote
1answer
26 views
Why isn't this working? (python-constraint)
My code
from constraint import *
abc = ((0, 1, 1), (1, 0, 0)) #((a1,b1,c1),(a2,b2,c2))
lim=10 #arbitrary
problem = Problem()
problem.addVariable("u", range(-lim,lim+1))
problem.addVariable("v", ...
7
votes
3answers
167 views
python - can lambda have more than one return
I know lambda doesn't have a return expression. Normally
def one_return(a):
#logic is here
c = a + 1
return c
can be written:
lambda a : a + 1
How about write this one in a lambda ...
0
votes
2answers
55 views
How to pass a parameter in a lambda function in python?
I want to set colors of an object, and don't want to create 10 functions for every color.
So, I just want to declare the colors and create 10 buttons and one function. Error message is:
...
0
votes
2answers
40 views
Python, cPickle, pickling lambda functions
I have to pickle an array of objects like this:
import cPickle as pickle
from numpy import sin, cos, array
tmp = lambda x: sin(x)+cos(x)
test = array([[tmp,tmp],[tmp,tmp]],dtype=object)
pickle.dump( ...
0
votes
2answers
47 views
Python — confused by numpy's piecewise function
I'm trying to implement a piecewise function in Python. Since I'm using quite a few tools from numpy, I simply import everything from it (i.e. from numpy import *). My piecewise function is defined as
...
0
votes
4answers
31 views
python lambda function of 0 arity
is it possible to write the following using Python's lambda notation?
def no(): return
the closest i can without a sytax error is
no = lambda _: no
which has the following property:
>>> ...
0
votes
3answers
47 views
Assign variable to local scope of function in Python
I'd like to assign a variable to the scope of a lambda that is called several times. Each time with a new instance of the variable. How do I do that?
f = lambda x: x + var.x - var.y
# Code needed ...
0
votes
1answer
37 views
will lambda func be 'cached'/remembered [duplicate]
map( lambda x: len(x), aLotOfData)
I am writing some code similar to above, will it actually be slower if I put in the lambda def in the same line? or I should assign to to a variable f to avoid ...
0
votes
1answer
43 views
simplify this python generation
I am new to python. Is there a way to simplify this:
def getDivs():
divs = soup.findAll(name = "div", attrs = {"class" : "resultCell"}, recursive = True)
for div in divs:
h2 = ...
0
votes
1answer
31 views
Python lambdas in Jinja2
I use Jinja2 as a website template engine, and all helper functions used in templates I've implemented as macros, but for one. This is it's Python code:
def arrow_class_from_deg(angle):
if angle ...
-2
votes
1answer
37 views
How can I use lambda complete this function?
I want to use lambda to finish the following function:
for i in range(0, len(testingList)):
testingList[i] = testing[i][1:-1]
I don't know how to use lambda to build it.
Thank you very much.
0
votes
3answers
49 views
Returning a dictionary based on a condition
I am trying to use a lambda or other python feature to return an dictionary if a condition is met, or none if not.
myDict = None
myDict = lambda c: {} if not myDict else myDict
Clearly, this not ...
0
votes
1answer
41 views
Python “with” Keyword in Lambda Functions
How is Python's with keyword expressed in a lambda function? Consider the following:
def cat (filename):
with open(filename, 'r') as f:
return f.read()
A failed attempt at a lambda ...
0
votes
2answers
41 views
tkinter button commands with lambda in Python
ive tried searching for a solution but couldn't find one that works. I have a 2d list of tkinter Buttons, and i want to change their Text when it is clicked by the mouse. I tried doing this:
def ...
1
vote
3answers
96 views
TypeError: <lambda>() takes no arguments (1 given)
I am a newbie to python programming and am still trying to figure out the use of lambda. Was worrking on some gui program after much googling i figured that i need to use this for buttons to work as i ...
