大约有 43,200 项符合查询结果（耗时：0.0523秒） [XML]
What is the preferred syntax for initializing a dict: curly brace literals {} or the dict() function
...e keys are valid Python identifiers.
This works:
a = {'import': 'trade', 1: 7.8}
a = dict({'import': 'trade', 1: 7.8})
This won't work:
a = dict(import='trade', 1=7.8)
>> SyntaxError: invalid syntax ^
...
Return index of greatest value in an array
...
12 Answers
12
Active
...
How can I convert spaces to tabs in Vim or Linux?
...
318
Using Vim to expand all leading spaces (wider than 'tabstop'), you were right to use retab but ...
Creating a zero-filled pandas data frame
...
140
You can try this:
d = pd.DataFrame(0, index=np.arange(len(data)), columns=feature_list)
...
Retrieving the last record in each group - MySQL
...
1021
MySQL 8.0 now supports windowing functions, like almost all popular SQL implementations. With...
Java Generate Random Number Between Two Given Values [duplicate]
...
418
You could use e.g. r.nextInt(101)
For a more generic "in between two numbers" use:
Random r =...
Take the content of a list and append it to another list
...
You probably want
list2.extend(list1)
instead of
list2.append(list1)
Here's the difference:
>>> a = range(5)
>>> b = range(3)
>>> c = range(2)
>>> b.append(a)
>>> b
[0, 1, 2, [0, 1, 2, 3, 4]]
>>> c.ex...
How do I test if a variable is a number in Bash?
...
1
2
Next
842
...
How to use a variable for the key part of a map
...
169
Use this:
def map = [(A):1, (X):2]
For the value-part it's even easier, since there is no a...
What is meant by 'first class object'?
...
11 Answers
11
Active
...