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Pandas read_csv low_memory and dtype options
...s cannot know it is only numbers, it will probably keep it as the original strings until it has read the whole file.
Specifying dtypes (should always be done)
adding
dtype={'user_id': int}
to the pd.read_csv() call will make pandas know when it starts reading the file, that this is only integers.
A...
How to insert a text at the beginning of a file?
...dd a line at the beginning of a file, you need to add \n at the end of the string in the best solution above.
The best solution will add the string, but with the string, it will not add a line at the end of a file.
sed -i '1s/^/your text\n/' file
...
Git: How to rebase to a specific commit?
...atively, check out the branch first with:
git checkout topic
Rebase Any String of Commits to a Target Commit
The basic form of the command we need, cribbed from the documentation, is:
git rebase --onto <Target> [<Upstream> [<Branch>]]
<Branch> is optional and all it do...
What is the effect of encoding an image in base64?
...
@Blender But in my case when i convert a 70kb bitmap to string its becoming 500kb.Its not 37%.I have compressed a 5mb image to 70kb and then convert that compressed image to string that become 500kb.
– KJEjava48
Apr 19 '17 at 6:05
...
Use of “this” keyword in formal parameters for static methods in C#
...above has a
"this" keyword before the first
parameter argument of type string.
This tells the compiler that this
particular Extension Method should be
added to objects of type "string".
Within the IsValidEmailAddress()
method implementation I can then
access all of the public
pro...
How do I find a “gap” in running counter with SQL?
...en this would find only 3. What I'd love it to find is 3-10 instead - basically the beginning and the end of every gap. I understand that I might have to write my own python script that leverages SQL (in my case MySql), but it would be nice if SQL could get me closer to what I want (I have a table w...
How to detect which one of the defined font was used in a web page?
...ty reliable way. Basically, an element is set to use a specific font and a string is set to that element. If the font set for the element does not exist, it takes the font of the parent element. So, what they do is measure the width of the rendered string. If it matches what they expected for the...
How to know when UITableView did scroll to bottom in iPhone
...st way is to test a point at the bottom of the screen and use this method call when ever the user scrolls (scrollViewDidScroll):
- (NSIndexPath *)indexPathForRowAtPoint:(CGPoint)point
Test a point near the bottom of the screen, and then using the indexPath it returns check if that indexPath is th...
Reshaping data.frame from wide to long format
...s melt/cast. Here is a solution with reshape, assuming your data frame is called d:
reshape(d,
direction = "long",
varying = list(names(d)[3:7]),
v.names = "Value",
idvar = c("Code", "Country"),
timevar = "Year",
times = 1950:1954)
...
How do DATETIME values work in SQLite?
... dates and times as TEXT, REAL, or INTEGER values:
TEXT as ISO8601 strings ("YYYY-MM-DD HH:MM:SS.SSS").
REAL as Julian day numbers, the number of days since noon in Greenwich on November 24, 4714 B.C. according to the proleptic Gregorian calendar.
INTEGER as Unix Time, the number of se...