This question already has answers here:
What algorithm does Python's built-in sort() method use?
(2 answers)
What is `lambda` in Python code? How does it work with `key` arguments to `sorted`, `sum` etc.?
(4 answers)
Understanding the map function
(6 answers)
Closed 1 year ago.
I found the following line of code which I'm unable to google as it has a custom function. Can someone please explain this?
list.sort(key=lambda v: map(int, v.split('.')))
I know this sorts a list but I want to understand which sort is it and how it works.
Related
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Can you add new statements to Python's syntax?
(13 answers)
Add new statements to Python without customizing the compiler
(2 answers)
Closed 4 years ago.
Can I create a statement in python 2.7?
Something similar to the print statement, that it's like a function, but gets the parameters without parenthesis.
This question already has answers here:
Python for-in loop preceded by a variable [duplicate]
(5 answers)
Explanation of how nested list comprehension works?
(11 answers)
Closed 4 years ago.
I am trying to figure out what the subsequent lines of python code actually do:
if (var1 and var1) in [ctl for key, value in list(uof.items()) for ctl, com in list(cd.items()) if com == 'spain']:
my_var= uof_map[var1 ]
I assume it executes some kind of the following logic:
for key, values in list(uof.items()):
for ctl, com in list(values.items()):
if com == 'spain':
But apparently the results do differ. Can someone please point me into the right direction?
Notes:
uof is a dictionary of dictionaries
value is a dictionary
This question already has answers here:
Python list sort in descending order
(6 answers)
Closed 5 years ago.
This is my code:
#这是一个有关旅行的程序
place=['北京天安门','西安兵马俑','香港游乐园','日本秋叶原']
print(place)
print(sorted(place))
print(place)
place.sorted(reverse=true)
print(place)
When I run my code, something Wrong happens.
place.sorted(reverse=true)
or
sorted(place)
Using the 2nd way, how can I give (reverse=true)?
Just use sorted(place, reverse=True).
This question already has answers here:
How do I prepend to a short python list?
(7 answers)
Closed 6 years ago.
Recently I was learning python,and I want to use the function that is opposite of append() function.How can I use the function insert an element in the first position of the list.Thank you!
Prepend doesn't exist, but you can simply use the insert method:
list.insert(0, element)
This question already has answers here:
Use of *args and **kwargs [duplicate]
(11 answers)
Closed 8 years ago.
In nltk. collocations I use this finder.apply_ngram_filter(lambda *w: w not in list). But I do not know what does mean the asterisk here. can someone explain me what the meaning of *w here? Because I know that the asterisk comes after the string and not before it.
It is argument unpacking :*args and **kwargs?. This means it is taking all the arguments you might pass to a function.