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Add column with constant value to pandas dataframe [duplicate]
...le times.
# Wrong
df['new'] = [[]] * len(df)
# Right
df['new'] = [[] for _ in range(len(df))]
Generating a copy: df.assign(new=0)
If you need a copy instead, use DataFrame.assign:
df.assign(new='y')
A B C new
0 x x x y
1 x x x y
2 x x x y
3 x x x y
And, if you ne...
What does Connect.js methodOverride do?
...to simulate DELETE and PUT, methodOverride is for that.
If you pass in the _method post parameter set to 'delete' or 'put', then you can use app.delete and app.put in Express instead of using app.post all the time (thus more descriptive, verbose):
Backend:
// the app
app.put('/users/:id', functio...
Create a .csv file with values from a Python list
...th open(..., 'wb') as myfile:
wr = csv.writer(myfile, quoting=csv.QUOTE_ALL)
wr.writerow(mylist)
Edit: this only works with python 2.x.
To make it work with python 3.x replace wb with w (see this SO answer)
with open(..., 'w', newline='') as myfile:
wr = csv.writer(myfile, quoting=c...
Why do we need the “finally” clause in Python?
...
It makes a difference if you return early:
try:
run_code1()
except TypeError:
run_code2()
return None # The finally block is run before the method returns
finally:
other_code()
Compare to this:
try:
run_code1()
except TypeError:
run_code2()
return...
How to empty a list?
...explanation of del, I'd refer to the docs: docs.python.org/reference/simple_stmts.html#the-del-statement
– fortran
Sep 9 '09 at 16:28
14
...
How to return 2 values from a Java method?
...
You can use SimpleEntry<type_of_value_1, type_of_value_2> from java.util.AbstractMap.SimpleEntry and use it with getKey() to get object 1 and getValue() to get object 2
– Crystalonics
Apr 28 '16 at 18:03
...
How to do scanf for single char in C [duplicate]
...mat. For example, if you input abc for an int such as: scanf("%d", &int_var); then abc will have to read and discarded. Consider:
#include <stdio.h>
int main(void)
{
int i;
while(1) {
if (scanf("%d", &i) != 1) { /* Input "abc" */
printf("Invalid input. Tr...
How to check Oracle database for long running queries
...SQL that is currently "ACTIVE":-
select S.USERNAME, s.sid, s.osuser, t.sql_id, sql_text
from v$sqltext_with_newlines t,V$SESSION s
where t.address =s.sql_address
and t.hash_value = s.sql_hash_value
and s.status = 'ACTIVE'
and s.username <> 'SYSTEM'
order by s.sid,t.piece
/
This shows locks....
Getting the closest string match
...f S2$)
Dim wordsS1$(), wordsS2$()
wordsS1 = SplitMultiDelims(S1, " _-")
wordsS2 = SplitMultiDelims(S2, " _-")
Dim word1%, word2%, thisD#, wordbest#
Dim wordsTotal#
For word1 = LBound(wordsS1) To UBound(wordsS1)
wordbest = Len(S2)
For word2 = LBound(wordsS2) To...
Remove empty array elements
...
As you're dealing with an array of strings, you can simply use array_filter(), which conveniently handles all this for you:
print_r(array_filter($linksArray));
Keep in mind that if no callback is supplied, all entries of array equal to FALSE (see converting to boolean) will be removed. So ...