大约有 46,000 项符合查询结果（耗时：0.0578秒） [XML]
Check whether an array is empty [duplicate]
...pty($errors)) {
}
array_filter() function's default behavior will remove all values from array which are equal to null, 0, '' or false.
Otherwise in your particular case empty() construct will always return true if there is at least one element even with "empty" value.
...
Pretty Printing a pandas dataframe
...
I've just found a great tool for that need, it is called tabulate.
It prints tabular data and works with DataFrame.
from tabulate import tabulate
import pandas as pd
df = pd.DataFrame({'col_two' : [0.0001, 1e-005 , 1e-006, 1e-007],
'column_3' : ['ABCD', ...
Is there a way of making strings file-path safe in c#?
...ered Dec 2 '08 at 7:35
Jonathan AllenJonathan Allen
61.5k6363 gold badges228228 silver badges416416 bronze badges
...
Validating email addresses using jQuery and regex
...EmailAddress(emailAddress) {
var pattern = /^([a-z\d!#$%&'*+\-\/=?^_`{|}~\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]+(\.[a-z\d!#$%&'*+\-\/=?^_`{|}~\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]+)*|"((([ \t]*\r\n)?[ \t]+)?([\x01-\x08\x0b\x0c\x0e-\x1f\x7f\x21\x23-\x5b\x5d-\x7e\u00A0-\uD7FF\uF900-\u...
django: BooleanField, how to set the default value to true?
...fields/#django.forms.Field.initial ) like
class MyForm(forms.Form):
my_field = forms.BooleanField(initial=True)
If you're using a ModelForm, you can set a default value on the model field ( https://docs.djangoproject.com/en/2.2/ref/models/fields/#default ), which will apply to the resulting M...
How to prevent ifelse() from turning Date objects into numeric objects
...irst this felt a little "hackish" to me. But now I just think of it as a small price to pay for the performance returns that I get from ifelse(). Plus it's still a lot more concise than a loop.
share
|
...
how do I make a single legend for many subplots with matplotlib?
... multiple subplots with matplotlib. That is, I have 9 plots on a 3x3 grid, all with the same for lines (of course, different values per line).
...
MySQL: selecting rows where a column is null
...
NULL = NULL is not really FALSE - it's NULL again. But it's not TRUE either, so IF(NULL = NULL) won't execute.
– Konerak
Jan 12 '11 at 19:50
...
Django admin: how to sort by one of the custom list_display fields that has no database field
How could I sort Customers, depending on number_of_orders they have?
3 Answers
3
...
How do I list all cron jobs for all users?
Is there a command or an existing script that will let me view all of a *NIX system's scheduled cron jobs at once? I'd like it to include all of the user crontabs, as well as /etc/crontab , and whatever's in /etc/cron.d . It would also be nice to see the specific commands run by run-parts in /e...