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How do I make a list of data frames?
... is done pretty easily when reading in files. Maybe you've got files data1.csv, data2.csv, ... in a directory. Your goal is a list of data.frames called mydata. The first thing you need is a vector with all the file names. You can construct this with paste (e.g., my_files = paste0("data", 1:5, ".csv...
How to write DataFrame to postgres table?
...s DB much faster than df.to_sql method and you won't need any intermediate csv file to store the df.
Create an engine based on your DB specifications.
Create a table in your postgres DB that has equal number of columns as the Dataframe (df).
Data in DF will get inserted in your postgres table.
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Output data from all columns in a dataframe in pandas [duplicate]
I have a csv file with the name params.csv . I opened up ipython qtconsole and created a pandas dataframe using:
7 Ans...
How to create a file in memory for user to download, but not through server?
... a download prompt. Otherwise, it will probably open in the browser.
For CSV, you can use:
<a href="data:application/octet-stream,field1%2Cfield2%0Afoo%2Cbar%0Agoo%2Cgai%0A">CSV Octet</a>
Try the jsFiddle demo.
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Only read selected columns
....g.: fread("data.txt", select = c(1:7), data.table = FALSE)
2) With read.csv.sql from the sqldf-package:
Another alternative is the read.csv.sql function from the sqldf package:
library(sqldf)
dat <- read.csv.sql("data.txt",
sql = "select Year,Jan,Feb,Mar,Apr,May,Jun from ...
source of historical stock data [closed]
...IS NO LONGER ACCURATE AS THE YAHOO FEED HAS CEASED TO EXIST
Using Yahoo's CSV approach above you can also get historical data!
You can reverse engineer the following example:
http://ichart.finance.yahoo.com/table.csv?s=YHOO&d=0&e=28&f=2010&g=d&a=3&b=12&c=1996&ignore...
How to convert a List into a comma separated string without iterating List explicitly [dupli
...
With Java 8:
String csv = String.join(",", ids);
With Java 7-, there is a dirty way (note: it works only if you don't insert strings which contain ", " in your list) - obviously, List#toString will perform a loop to create idList but it does n...
How to save MySQL query output to excel or .txt file? [duplicate]
...
From Save MySQL query results into a text or CSV file:
MySQL provides an easy mechanism for writing the results of a select
statement into a text file on the server. Using extended options of
the INTO OUTFILE nomenclature, it is possible to create a comma
sepa...
How do I load a file from resource folder?
...ntextClassLoader();
InputStream is = classloader.getResourceAsStream("test.csv");
If the above doesn't work, various projects have been added the following class: ClassLoaderUtil1 (code here).2
Here are some examples of how that class is used:
src\main\java\com\company\test\YourCallingClass.ja...
R command for setting working directory to source file location in Rstudio
...s/proyect1").
Once you set that, you can navigate to a subdirectory: read.csv("DATA/mydata.csv"). Is the same as read.csv("D:/Documents/proyect1/DATA/mydata.csv").
If you want to navigate to a parent folder, you can use "../".
For example: read.csv("../olddata/DATA/mydata.csv") which is the same ...