When and why should I use lambda functions?

Question

I'm trying to figure out how and when Python lambdas should be used, and why should I use them instead of regular functions.

Answer 1

when you are in hurry or near deadline.

Answer 2

When there is no point in defining a regular, named function, i.e. if you only use it once - as a key in sorted() or in map(), filter(), reduce() situations.

Answer 3

- Functional programming
- Little callback function
- ...

https://en.wikipedia.org/wiki/Functional_programming#JUMP_LINK__&&__Python__&&__JUMP_LINK

Answer 4

# I find they are handy to
# keep simple operations close
# to associated code sometimes

import tkinter as tk

root = tk.Tk()
tk.Button(text='Double click Me').grid()
b=root.winfo_children()[0]
b.bind("<Double-1>",lambda event:b.configure(text='clicked twice'))
tk.Button(text='text here',
command=lambda:anon_click_command('top')).grid()
tk.Button(text='text here',
command=lambda:anon_click_command('bottom')).grid()

def anon_click_command(button_id):
c= root.winfo_children()[1:]
for but in c:
if but['text']!='text here':
but['text']='text here'

if button_id =='top':
c[0].configure(text='changed top')
elif button_id =='bottom':
c[1].configure(text='changed bottom')

root.mainloop()

Answer 5

@Agus damn true 😂😂😂

Answer 6

List Comprehensions 5.1.3 says that Lambda functions can be used to calculate List Comprehensions without any "side effects". (https://docs.python.org/3/tutorial/datastructures.html)