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Efficiently updating database using SQLAlchemy ORM
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184
SQLAlchemy's ORM is meant to be used together with the SQL layer, not hide it. But you do have...
List All Redis Databases
...atabases is fixed, and set in the configuration file. By default, you have 16 databases. Each database is identified by a number (not a name).
You can use the following command to know the number of databases:
CONFIG GET databases
1) "databases"
2) "16"
You can use the following command to list ...
Iterate a list with indexes in Python
...ar I've seen the function (or method) that takes a list, like this [3, 7, 19] and makes it into iterable list of tuples, like so: [(0,3), (1,7), (2,19)] to use it instead of:
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SVN undo delete before commit
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145
svn revert deletedDirectory
Here's the documentation for the svn revert command.
EDIT
If dele...
Get number of digits with JavaScript
...d like to know how many digits var number has. For example: If number = 15; my function should return 2 . Currently, it looks like this:
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Creating an R dataframe row-by-row
...code in R.
If you can, allocate your entire data.frame up front:
N <- 1e4 # total number of rows to preallocate--possibly an overestimate
DF <- data.frame(num=rep(NA, N), txt=rep("", N), # as many cols as you need
stringsAsFactors=FALSE) # you don't know levels y...
Can I query MongoDB ObjectId by date?
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12 Answers
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Guards vs. if-then-else vs. cases in Haskell
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122
From a technical standpoint, all three versions are equivalent.
That being said, my rule of t...
Linux command (like cat) to read a specified quantity of characters
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194
head works too:
head -c 100 file # returns the first 100 bytes in the file
..will extract ...
How do I check that a number is float or integer?
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