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Comparing two dataframes and getting the differences
... behaviour for pd.concat(), here's the docs pandas.pydata.org/pandas-docs/stable/merging.html
– Thanos
Apr 17 '16 at 18:35
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How to change the type of a field?
...big deal no matter how you do it. If you were using SQL and this was a big table you would probably have to take some down time.
– Gates VP
Jun 28 '16 at 18:16
...
How do you get the length of a list in the JSF expression language?
...java.sun.com/jsp/jstl/functions" prefix="fn"%>
<h:outputText value="Table Size = #{fn:length(SystemBean.list)}"/>
On screen it displays the Table size
Example: Table Size = 5
share
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im...
Cookie overflow in rails application?
...xample.
Here is the steps
Generate a migration that creates the session table
rake db:sessions:create
Run the migration
rake db:migrate
Modify config/initializers/session_store.rb from
(App)::Application.config.session_store :cookie_store, :key => 'xxx'
to
(App)::Application.config.ses...
How to read data when some numbers contain commas as thousand separator?
...
You can have read.table or read.csv do this conversion for you semi-automatically. First create a new class definition, then create a conversion function and set it as an "as" method using the setAs function like so:
setClass("num.with.commas...
What does “exec sp_reset_connection” mean in Sql Server Profiler? [duplicate]
...llocated memory
owned by the connection
Clears any work or temporary
tables that are created by the
connection
Kills all global cursors owned by the
connection
Closes any open SQL-XML handles that are open
Deletes any open SQL-XML related work tables
Closes all system tables
Clo...
What is NoSQL, how does it work, and what benefits does it provide? [closed]
...past few years, people started to question this dogma. People wondered if tables with rows and columns are really the only way to represent data. People started thinking and coding, and came up with many new concepts how data could be organized. And they started to create new database systems desig...
Are negative array indexes allowed in C?
...want to use negative indexes, I have used them in two contexts:
Having a table of combinatorial numbers that tells you comb[1][-1] = 0; you can always check indexes before accessing the table, but this way the code looks cleaner and executes faster.
Putting a centinel at the beginning of a table. ...
How do I find an element that contains specific text in Selenium Webdriver (Python)?
...substitutes a source character to its desired form, by using a translation table.
Constructing a table of all upper case characters will effectively transform the node's text to its lower() form - allowing case-insensitive matching (here's just the prerogative):
[
contains(
translate(text(),...
best practice to generate random token for forgot password
...rch in about a week's time for a low-budget attacker:
mt_rand() is predictable (and only adds up to 31 bits of entropy)
uniqid() only adds up to 29 bits of entropy
md5() doesn't add entropy, it just mixes it deterministically
Since a 56-bit DES key can be brute-forced in about 24 hours, and an a...