python list get default
An easy solution is to transform the list into a dict. Then you can use dict.get : table = dict(enumerate(the_list)) return table.get(i). You can even set another default value than None , using the second argument to dict.get . For example, use table.ge, x[index] if len(x) > index else default. to support negative indices we can use: x[index] if -len(l) <= index < len(l) else default., In the Python spirit of "ask for forgiveness, not permission", here's one way: try: b = a[4] except IndexError: b = 'sss' ..., In the Python spirit of "ask for forgiveness, not permission", here's one way: try: b = a[4] except IndexError: b = 'sss'., You can use next() : >>> a = [None, None, None, 1, 2, 3, 4, 5] >>> next(item for item in a if item is not None) 1. If the list contains only Nones, it will throw StopIteration exception. If you want to have a default value in this case,, The .get method allows you to query the value associated with a name, not directly access the 37th item in the dictionary (which would be more like what you're asking of your list). Of course, you can easily implement this yourself: def safe_list_get, One of the many cool things about Python is that you can often use builtin functions to either get a value from a dictionary (or an object with getattr ) or default to a specified value. Unfortunately lists do not provide such a function. The simplest us, The best method is to use collections.defaultdict with a list default: from collections import defaultdict dct = defaultdict(list). Then just use: dct[key].append(some_value). and the dictionary will create a new list for you if the key is not yet in the, It's not dict.get( i, [] ) that's returning None , it's append . You probably want to use dict.setdefault(i, []).append(j) or just use a defaultdict in the first place. Here's how you would do it: d = } for i in range( 0, 10 ): for j in r
| 相關軟體 Python 資訊 | |
|---|---|
 python list get default 相關參考資料
Get value at listarray index or "None" if out of range in Python ...
An easy solution is to transform the list into a dict. Then you can use dict.get : table = dict(enumerate(the_list)) return table.get(i). You can even set another default value than None , using the ... https://stackoverflow.com How to get the nth element of a python list or a default if not ...
x[index] if len(x) > index else default. to support negative indices we can use: x[index] if -len(l) <= index < len(l) else default. https://stackoverflow.com list - Getting a default value on index out of range in Python - Stack ...
In the Python spirit of "ask for forgiveness, not permission", here's one way: try: b = a[4] except IndexError: b = 'sss' ... https://stackoverflow.com list - Getting a default value on index out of range in Python ...
In the Python spirit of "ask for forgiveness, not permission", here's one way: try: b = a[4] except IndexError: b = 'sss'. https://stackoverflow.com python - Getting the first non None value from list - Stack Overflow
You can use next() : >>> a = [None, None, None, 1, 2, 3, 4, 5] >>> next(item for item in a if item is not None) 1. If the list contains only Nones, it will throw StopIteration excep... https://stackoverflow.com python - Why doesn't list have safe "get" method like dictionary ...
The .get method allows you to query the value associated with a name, not directly access the 37th item in the dictionary (which would be more like what you're asking of your list). Of course, yo... https://stackoverflow.com Python Snippet – Get List Item or Get Default – Chris West's Blog
One of the many cool things about Python is that you can often use builtin functions to either get a value from a dictionary (or an object with getattr ) or default to a specified value. Unfortunatel... http://cwestblog.com Python: list() as default value for dictionary - Stack Overflow
The best method is to use collections.defaultdict with a list default: from collections import defaultdict dct = defaultdict(list). Then just use: dct[key].append(some_value). and the dictionary will... https://stackoverflow.com Python: Using Dictionary get method to return empty list by ...
It's not dict.get( i, [] ) that's returning None , it's append . You probably want to use dict.setdefault(i, []).append(j) or just use a defaultdict in the first place. Here's how you... https://stackoverflow.com |