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How to index characters in a Golang string?
...ay reconvert the string on each iteration for, O(n²). Just do for _, r := range word { fmt.Printf("%c", r) }. If you really wanted to loop with an index for x := 0; x < limit; x++. Please learn the basics of a language before answering questions.
– Dave C
A...
Delete the first three rows of a dataframe in pandas
... works but returns duplicate columns in the index df=pd.DataFrame({'v':np.arange(10).tolist()*2,'g':['a']*10+['b']*10});df.groupby('g').apply(lambda x: x.iloc[3:])
– citynorman
Aug 6 '17 at 22:24
...
Replacing all non-alphanumeric characters with empty strings
...e that [^a-zA-Z] will replace characters not being itself in the character range A-Z/a-z. That means special characters like é, ß etc. or cyrillic characters and such will be removed.
If the replacement of these characters is not wanted use pre-defined character classes instead:
str.replaceAl...
List to array conversion to use ravel() function
...
create an int array and a list
from array import array
listA = list(range(0,50))
for item in listA:
print(item)
arrayA = array("i", listA)
for item in arrayA:
print(item)
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imp...
Regular expression for floating point numbers
...ping can get very confusing. If the language you are working with supports raw strings, then you should use those to cut down on the number of backslashes, but not all languages do (most notably: Java). Fortunately, there's an alternative that will work some of the time:
String correctPattern = "[....
Delete newline in Vim
...nly happen on the line the cursor is on. Alternatively, you can specify a range such as :11,15s/\n/ (lines 11-15) or :,+7s/\n/ (this line and the next seven) or :-3,s/\n/ (previous three lines and this one)... you get the idea
– Tristan
Oct 21 '10 at 1:03
...
Getting Http Status code number (200, 301, 404, etc.) from HttpWebRequest and HttpWebResponse
...
You have to be careful, server responses in the range of 4xx and 5xx throw a WebException. You need to catch it, and then get status code from a WebException object:
try
{
wResp = (HttpWebResponse)wReq.GetResponse();
wRespStatusCode = wResp.StatusCode;
}
catch (We...
Javascript: Round up to the next multiple of 5
I need a utility function that takes in an integer value (ranging from 2 to 5 digits in length) that rounds up to the next multiple of 5 instead of the nearest multiple of 5. Here is what I got:
...
How fast is D compared to C++?
... -boundscheck=off <sourcefile>
Results
The results (screenshot of raw console output) of each version of the source as follows:
scalar.cpp (original C++):
allocation: 2 ms
random generation: 12 ms
result: 29248300000
time: 2582 ms
C++ sets the standard at 2582 ms.
scalar.d (modifi...
List of Big-O for PHP functions
...res a linear poll.
Obvious Big-O:
array_fill O(n)
array_fill_keys O(n)
range O(n)
array_splice O(offset + length)
array_slice O(offset + length) or O(n) if length = NULL
array_keys O(n)
array_values O(n)
array_reverse O(n)
array_pad O(pad_size)
array_flip O(n)
array_sum O(n)
array_produ...