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How to read a CSV file into a .NET Datatable
How can I load a CSV file into a System.Data.DataTable , creating the datatable based on the CSV file?
22 Answers
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What is the difference between join and merge in Pandas?
...e the main differences between df.join() and df.merge():
lookup on right table: df1.join(df2) always joins via the index of df2, but df1.merge(df2) can join to one or more columns of df2 (default) or to the index of df2 (with right_index=True).
lookup on left table: by default, df1.join(df2) uses...
Is there a way to get rid of accents and convert a whole string to regular letters?
...(string, Normalizer.Form.NFD);
// or Normalizer.Form.NFKD for a more "compatable" deconstruction
This will separate all of the accent marks from the characters. Then, you just need to compare each character against being a letter and throw out the ones that aren't.
string = string.replaceAll("[...
What is a NullReferenceException, and how do I fix it?
...that C# has the concept of nullable datatypes for variables (like database tables can have nullable fields) - you can assign null to them to indicate there is no value stored in it, for example int? a = null; where the question mark indicates it is allowed to store null in variable a. You can check ...
MySQL and GROUP_CONCAT() maximum length
...T SESSION group_concat_max_len = 1000000;
select group_concat(column) from table group by column
You can do this even in sharing hosting, but when you use an other session, you need to repeat the SET SESSION command.
share...
How do you connect to multiple MySQL databases on a single webpage?
...ery database 1 pass the first link identifier:
mysql_query('select * from tablename', $dbh1);
and for database 2 pass the second:
mysql_query('select * from tablename', $dbh2);
If you do not pass a link identifier then the last connection created is used (in this case the one represented by $d...
How may I align text to the left and text to the right in the same line?
...untime that it looks bad.
What I like to do is simply create a single row table and apply the right float on the second cell. No need to apply a left-align on the first, that happens by default. This handles overlap perfectly by word-wrapping.
HTML
<table style="width: 100%;">
<tr>&...
PostgreSQL - fetch the row which has the Max value for a column
I'm dealing with a Postgres table (called "lives") that contains records with columns for time_stamp, usr_id, transaction_id, and lives_remaining. I need a query that will give me the most recent lives_remaining total for each usr_id
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Frequency table for a single variable
One last newbie pandas question for the day: How do I generate a table for a single Series?
4 Answers
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Get properties and values from unknown object
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Here's something I use to transform an IEnumerable<T> into a DataTable that contains columns representing T's properties, with one row for each item in the IEnumerable:
public static DataTable ToDataTable<T>(IEnumerable<T> items)
{
var table = CreateDataTableForPropertiesO...