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How to read a text file reversely with iterator in C#
I need to process a large file, around 400K lines and 200 M. But sometimes I have to process from bottom up. How can I use iterator (yield return) here? Basically I don't like to load everything in memory. I know it is more efficient to use iterator in .NET.
...
How do I use Maven through a proxy?
...mething like this:
<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0
http://maven.apache.org/xsd/settings-1.0.0.xsd">
[...]
<proxies>
<p...
Cast Object to Generic Type for returning
...rSpaceTrucker
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59
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pandas read_csv and filter columns with usecols
...andas as pd
from StringIO import StringIO
csv = r"""dummy,date,loc,x
bar,20090101,a,1
bar,20090102,a,3
bar,20090103,a,5
bar,20090101,b,1
bar,20090102,b,3
bar,20090103,b,5"""
df = pd.read_csv(StringIO(csv),
header=0,
index_col=["date", "loc"],
usecols=["date", "loc", "x"],
...
Purge Kafka Topic
...;zkhost>:2181 --alter --topic <topic name> --config retention.ms=1000
And in newer Kafka releases, you can also do it with kafka-configs --entity-type topics
kafka-configs.sh --zookeeper <zkhost>:2181 --entity-type topics --alter --entity-name <topic name> --add-config retent...
String concatenation vs. string substitution in Python
...
... return "%s%s/%d" % (DOMAIN, QUESTIONS, n)
...
>>> so_q_sub(1000)
'http://stackoverflow.com/questions/1000'
>>> def so_q_cat(n):
... return DOMAIN + QUESTIONS + '/' + str(n)
...
>>> so_q_cat(1000)
'http://stackoverflow.com/questions/1000'
>>> t1 = timeit.Tim...
how do I initialize a float to its max/min value?
...west possible positive value. In other words the positive value closest to 0 that can be represented. The lowest possible value is the negative of the maximum possible value.
There is of course the std::max_element and min_element functions (defined in <algorithm>) which may be a better choic...
Clearing a string buffer/builder after loop
...ete method as follows:
StringBuffer sb = new StringBuffer();
for (int n = 0; n < 10; n++) {
sb.append("a");
// This will clear the buffer
sb.delete(0, sb.length());
}
Another option (bit cleaner) uses setLength(int len):
sb.setLength(0);
See Javadoc for more info:
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dplyr: “Error in n(): function should not be called directly”
...
120
I presume you have dplyr and plyr loaded in the same session. dplyr is not plyr. ddply is not a ...
JSON.parse unexpected character error
...rsing an already-parsed object :)
var obj1 = JSON.parse('{"creditBalance":0,...,"starStatus":false}');
// ^ ^
// if you want to parse, the input should be a string
var obj2 = {"creditBalance":0,...,"starStatus":false};...