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Lazy Method for Reading Big File in Python?
..., you can to use the file object itself as lazy generator:
with open('big.csv') as f:
for line in f:
process(line)
However, I once ran into a very very big (almost) single line file, where the row separator was in fact not '\n' but '|'.
Reading line by line was not an option, but I ...
Create an empty data.frame
...ames)
Alternatively specifying the col.names as a string:
df <- read.csv(text="Date,File,User", colClasses = colClasses)
Thanks to Richard Scriven for the improvement
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Change one value based on another value in pandas
...re.
Assuming you can load your data directly into pandas with pandas.read_csv then the following code might be helpful for you.
import pandas
df = pandas.read_csv("test.csv")
df.loc[df.ID == 103, 'FirstName'] = "Matt"
df.loc[df.ID == 103, 'LastName'] = "Jones"
As mentioned in the comments, you c...
How can I transform string to UTF-8 in C#?
...
Use the below code snippet to get bytes from csv file
protected byte[] GetCSVFileContent(string fileName)
{
StringBuilder sb = new StringBuilder();
using (StreamReader sr = new StreamReader(fileName, Encoding.Default, true))
{
St...
Include headers when using SELECT INTO OUTFILE?
...ment with lucek's answer and export dynamically table with columns name in CSV :
--If your table has too many columns
SET GLOBAL group_concat_max_len = 100000000;
--Prepared statement
SET @SQL = ( select CONCAT('SELECT * INTO OUTFILE \'YOUR_PATH\' FIELDS TERMINATED BY \',\' OPTIONALLY ENCLOSED BY \...
Stock ticker symbol lookup API [closed]
...ymbols, names, quotes, and all sorts of other data. Data is returned as a .CSV so you can request multiple symbols in one query.
So if you send:
http://finance.yahoo.com/d/quotes.csv?s=MSFT+F+ATT&f=sn
You'll get back something like:
"MSFT","Microsoft Corp"
"F","FORD MOTOR CO"
"ATT","AT&...
如何将 excel 中数据按坐标读取并显示到其他屏幕? - App Inventor 2 中文...
...有excel操作相关功能,也没有现成的拓展。 目前只能处理csv(不带样式的excel)或txt纯文本数据,可考虑将excel保存为csv文件,将csv文件导入“数据文件”组件,从组件中获取相关数据。
其中,数据结构的设计是关键,得好好考...
AppInventor如何实现通过扫二维码导入表格数据 - App Inventor 2 拓展 - 清...
...上面条码组件的事件中获取。
3、访问远程url获取表格csv数据:
使用Web客户端组件访问url获取数据。数据格式建议采用csv(逗号分隔)格式。
4、解析数据并展示:
推荐使用TableView拓展展示csv表格数据。
Compress files while reading data from STDIN
...ad data as input and redirect the compressed to output file i.e.
cat test.csv | gzip > test.csv.gz
cat test.csv will send the data as stdout and using pipe-sign gzip will read that data as stdin. Make sure to redirect the gzip output to some file as compressed data will not be written to the t...
How to find where a method is defined at runtime?
...#crime>
If you're on Ruby 1.9+, you can use source_location
require 'csv'
p CSV.new('string').method(:flock)
# => #<Method: CSV#flock>
CSV.new('string').method(:flock).source_location
# => ["/path/to/ruby/1.9.2-p290/lib/ruby/1.9.1/forwardable.rb", 180]
Note that this won't work...
