python - How to break a large CSV data file into individual data files? -

-

i have csv file first row of contains variables names , rest of rows contains data. what's way break files each containing 1 variable in python? solution going robust? e.g. if input file 100g in size? trying perform divide conquer strategy new python. in advance help!

the input files looks like

var1,var2,var3 1,2,hello 2,5,yay ...

i want create 3 (or many variables) files var1.csv, var2.csv, var3.csv files resemble file1

var1 1 2 ...

file2

var2 2 5 ...

file3

var3 hello yay

as lomg number of columns isn't absurdly huge (larger number of files can have open @ once on platform), number of rows, , total size, no big deal (as long of course have ample free space on disk;-) since you'll processing column @ time -- suggest following code:

import csv  def splitit(inputfilename):   open(inputfilename, 'rb') inf:     inrd = csv.reader(inf)     names = next(inrd)     outfiles = [open(n+'.csv', 'wb') n in names]     ouwr = [csv.writer(w) w in outfiles]     w, n in zip(ouwr, names):       w.writerow([n])     row in inrd:       w, r in zip(ouwr, row):         ouwr.writerow([r])     o in outfiles: o.close()

Comments

Post a Comment

Popular posts from this blog

c++ - How do I get a multi line tooltip in MFC -

-
right now, have tool tip pops when hover on edit box. problem tool tip contains multiple error messages , in 1 long line. need have each error message on own line. error messages contained in cstring new line seperating them. my existing code below. bool ontooltiptext(uint, nmhdr* pnmhdr, lresult* presult) { assert(pnmhdr->code == ttn_needtexta || pnmhdr->code == ttn_needtextw); // need handle both ansi , unicode versions of message tooltiptexta* pttta = (tooltiptexta*)pnmhdr; tooltiptextw* ptttw = (tooltiptextw*)pnmhdr; // tchar szfulltext[256]; cstring strtiptext=_t(""); uint nid = pnmhdr->idfrom; if (pnmhdr->code == ttn_needtexta && (pttta->uflags & ttf_idishwnd) || pnmhdr->code == ttn_needtextw && (ptttw->uflags & ttf_idishwnd)) { // idfrom hwnd of tool nid = ::getdlgctrlid((hwnd)nid); } //m_errprojaccel[ch] contains 1 or more error messages each...
Read more

asp.net - In javascript how to find the height and width -

-
i having .aspx , masterpage page. in masterpage loading aspx page . in aspx page design using generating table structure using code-behind server in javascript how find height , width . regards, kumar if you're looking table height , width, should it var tbl = document.getelementbyid('tbldemo'); alert(tbl.offsetwidth + '\n' + tbl.offsetheight);
Read more

c# - DataTable to EnumerableRowCollection -

-
i have datatable according client requirement can contain invalid date "00/00/1999",null,empty string.(typed datset) when collect them enumerables wish convert of invalid forms empty string. (i.e) enumerablerowcollection<datarow> query = order in _table.asenumerable() select new { orderdate= string.isnullorempty(convert.tostring(order.field<datetime>("orderdate")) || (how check date invalid date) ? string.empty : order.field<datetime>("orderdate") } how check whether date valid date or not? datetime.tryparse...like given current code: datetime date; enumerablerowcollection<datarow> query = order in _table.asenumerable() select new { orderdate= string.isnullorempty(convert.tostring(order.field<datetime>("orderdate")) || !datetime.tryparse(convert.tostring(order.field<datetime...
Read more