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How to save a dictionary to a file?
I have problem with changing a dict value and saving the dict to a text file (the format must be same), I only want to change the member_phone field.
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How to run Maven from another directory (without cd to project dir)?
... editor after snippets, if snippets enabled
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Writing outputs to log file and console
In Unix shell, I have a env file ( env file defines the parameters required for running the user script like log file name and path, redirect outputs and errors to log file, database connection details, etc ) which redirects all the outputs ( echo messages ) and errors to the log file from the execu...
What does “O(1) access time” mean?
... like 14 nanoseconds, or three minutes no matter the amount of data in the set.
O(n) means it takes an amount of time linear with the size of the set, so a set twice the size will take twice the time. You probably don't want to put a million objects into one of these.
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Properties file in python (similar to Java Properties)
...neral not going to pass for valid python code. One alternative is to just set your properties in a python file, and use valid python (e.g: MEDIA_ROOT='/foo') ...
– danbgray
May 11 '12 at 21:19
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Convert String to Calendar Object in Java
... = new SimpleDateFormat("EEE MMM dd HH:mm:ss z yyyy", Locale.ENGLISH);
cal.setTime(sdf.parse("Mon Mar 14 16:02:37 GMT 2011"));// all done
note: set Locale according to your environment/requirement
See Also
Javadoc
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MySQL DROP all tables, ignoring foreign keys
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I found the generated set of drop statements useful, and recommend these tweaks:
Limit the generated drops to your database like this:
SELECT concat('DROP TABLE IF EXISTS `', table_name, '`;')
FROM information_schema.tables
WHERE table_schem...
Python assigning multiple variables to same value? list behavior
...1 is actually calling a method on the list object. (It's equivalent to a.__setitem__(0, 1).) So, it's not really rebinding anything at all. It's like calling my_object.set_something(1). Sure, likely the object is rebinding an instance attribute in order to implement this method, but that's not what'...
Should all Python classes extend object?
I have found that both of the following work:
6 Answers
6
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What's the fastest way to merge/join data.frames in R?
...eSQL databases as well.
library(plyr)
library(data.table)
library(sqldf)
set.seed(123)
N <- 1e5
d1 <- data.frame(x=sample(N,N), y1=rnorm(N))
d2 <- data.frame(x=sample(N,N), y2=rnorm(N))
g1 <- sample(1:1000, N, replace = TRUE)
g2<- sample(1:1000, N, replace = TRUE)
d <- data.fram...