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How to extract the substring between two markers?
...fdAAA1234ZZZuijjk'
m = re.search('AAA(.+?)ZZZ', text)
if m:
found = m.group(1)
# found: 1234
or:
import re
text = 'gfgfdAAA1234ZZZuijjk'
try:
found = re.search('AAA(.+?)ZZZ', text).group(1)
except AttributeError:
# AAA, ZZZ not found in the original string
found = '' # apply y...
SQL Server 2008: How to query all databases sizes?
...SELECT database_id, SUM(size) RowSize FROM sys.master_files WHERE type = 0 GROUP BY database_id, type) mfrows ON mfrows.database_id = db.database_id
LEFT JOIN (SELECT database_id, SUM(size) LogSize FROM sys.master_files WHERE type = 1 GROUP BY database_id, type) mflog ON mflog.database_id = db.d...
Finding duplicate values in a SQL table
...
SELECT
name, email, COUNT(*)
FROM
users
GROUP BY
name, email
HAVING
COUNT(*) > 1
Simply group on both of the columns.
Note: the older ANSI standard is to have all non-aggregated columns in the GROUP BY but this has changed with the idea of "functiona...
What is an intuitive explanation of the Expectation Maximization technique? [closed]
...can be found here.
Suppose we have some data sampled from two different groups, red and blue:
Here, we can see which data point belongs to the red or blue group. This makes it easy to find the parameters that characterise each group. For example, the mean of the red group is around 3, the mean...
ggplot2 keep unused levels barplot
...is:
library(ggplot2)
df <- data.frame(type=c("A", "A", "A", "B", "B"), group=rep("group1", 5))
df1 <- data.frame(type=c("A", "A", "A", "B", "B", "A", "A", "C", "B", "B"), group=c(rep("group1", 5),rep("group2", 5)))
df$type <- factor(df$type, levels=c("A","B", "C"))
df1$type <- factor(df...
Get “Value” property in IGrouping
...
The group implements IEnumerable<T> - In the general case, just call foreach over the group. In this case, since you need a List<T>:
list.Add(new DespatchGroup(group.Key, group.ToList());
...
How to do SELECT COUNT(*) GROUP BY and ORDER BY in Django?
...r_by('total')
values() : specifies which columns are going to be used to "group by"
Django docs:
"When a values() clause is used to constrain the columns that are
returned in the result set, the method for evaluating annotations is
slightly different. Instead of returning an annotated result for e...
what is the difference between ?:, ?! and ?= in regex?
... expression from the entire match while ?: just doesn't create a capturing group. So for example a(?:b) will match the "ab" in "abc", while a(?=b) will only match the "a" in "abc". a(b) would match the "ab" in "abc" and create a capture containing the "b".
...
How to loop through an array containing objects and access their properties
...
6. Count the number of each category
const people = [
{name: 'John', group: 'A'},
{name: 'Andrew', group: 'C'},
{name: 'Peter', group: 'A'},
{name: 'James', group: 'B'},
{name: 'Hanna', group: 'A'},
{name: 'Adam', group: 'B'}];
const groupInfo = people.reduce((groups,...
How to split a string in Java
...r to end up in left hand side, use positive lookbehind by prefixing ?<= group on the pattern.
String string = "004-034556";
String[] parts = string.split("(?<=-)");
String part1 = parts[0]; // 004-
String part2 = parts[1]; // 034556
In case you want to have the split character to end up in ...