从CSV文件读取

Question

I have a CSV file containing many rows and columns 2 of which are similar to:

Horizontal-1 Acc. Filename      Horizontal-2 Acc. Filename
 RSN88_SFERN_FSD172.AT2          RSN88_SFERN_FSD262.AT2 
 RSN164_IMPVALL.H_H-CPE147.AT2   RSN164_IMPVALL.H_H-CPE237.AT2 
 RSN755_LOMAP_CYC195.AT2         RSN755_LOMAP_CYC285.AT2 
 RSN1083_NORTHR_GLE170.AT2       RSN1083_NORTHR_GLE260.AT2 
 RSN1614_DUZCE_1061-N.AT2        RSN1614_DUZCE_1061-E.AT2 
 RSN1633_MANJIL_ABBAR--L.AT2     RSN1633_MANJIL_ABBAR--T.AT2 
 RSN3750_CAPEMEND_LFS270.AT2     RSN3750_CAPEMEND_LFS360.AT2 
 RSN3757_LANDERS_NPF090.AT2      RSN3757_LANDERS_NPF180.AT2
 RSN3759_LANDERS_WWT180.AT2      RSN3759_LANDERS_WWT270.AT2 
 RSN4013_SANSIMEO_36258021.AT2   RSN4013_SANSIMEO_36258111.AT2 
 RSN4841_CHUETSU_65004NS.AT2     RSN4841_CHUETSU_65004EW.AT2 
 RSN4843_CHUETSU_65006NS.AT2     RSN4843_CHUETSU_65006EW.AT2 
 RSN4844_CHUETSU_65007NS.AT2     RSN4844_CHUETSU_65007EW.AT2 
 RSN4848_CHUETSU_65011NS.AT2     RSN4848_CHUETSU_65011EW.AT2

In the CSV file I wanna look for the headers "Horizontal-1 Acc. Filename and Horizontal-2 Acc. Filename" and then line by line get the names of each row under these headers one at a time ?

Any suggestion ?

Thanks RG.

Answer 1

package require csv
package require struct::matrix

::struct::matrix m
m add columns 2

set chan [open data.csv]
::csv::read2matrix $chan m
close $chan

lassign [m get row 0] header1 header2

for {set r 1} {$r < [m rows]} {incr r} {
    puts -nonewline [format {%s = %-30s  } $header1 [m get cell 0 $r]]
    puts [format {%s = %s} $header2 [m get cell 1 $r]]
}

m destroy

I find that the easiest way to deal with csv data sets is by using a matrix . A matrix is sort of a two-dimensional vector with built-ins for searching, sorting and rearranging columns and rows.

First, create a matrix and call it m . It will have two columns from the beginning, but no rows yet.

::struct::matrix m
m add columns 2

Open a channel to read the data file. Pass the channel and the matrix name to the ::csv::read2matrix command. This command will read the csv data and create a matrix row for each data row. The data fields are stored in the columns.

set chan [open data.csv]
::csv::read2matrix $chan m
close $chan

To get the header strings, retrieve row 0.

lassign [m get row 0] header1 header2

To iterate over the data rows, go from 1 (if we didn't have headers, 0) to just under m rows , which is the number of rows in the matrix.

There is a handy report facility that works well with matrices, but I'll just use a for loop here. I'm guessing how you want the data presented:

for {set r 1} {$r < [m rows]} {incr r} {
    puts -nonewline [format {%s = %-30s  } $header1 [m get cell 0 $r]]
    puts [format {%s = %s} $header2 [m get cell 1 $r]]
}

If you're done with the matrix, you might as well destroy it.

m destroy

---

Solution for the specific problem in the comments.

package require csv
package require struct::matrix

::struct::matrix m

set chan [open foo.csv]
::csv::read2matrix $chan m , auto
close $chan

set f1 [m search column 0 "Result ID"]
set headerRow [lindex $f1 0 1]
set f2 [m search rect 0 $headerRow 0 [expr {[m rows] - 1}] ""]
set f3 [m search row $headerRow "Horizontal-1 Acc. Filename"]
set f4 [m search row $headerRow "Horizontal-2 Acc. Filename"]

set top [expr {$headerRow + 1}]
set bottom [expr {[lindex $f2 0 1] - 1}]
set left [lindex $f3 0 0]
set right [lindex $f4 0 0]

puts [format {Vector=[ %s ]} [concat {*}[m get rect $left $top $right $bottom]]]
m destroy

Obviously, you need to change the filename to the correct name. There is no error handling: in such a simple script it's better to just have the script fail and correct whatever went wrong.

---

Solution to the second problem, comments below:

package require csv
package require struct::matrix

::struct::matrix m

set chan [open _SearchResults.csv]
::csv::read2matrix $chan m , auto
close $chan

set f1 [m search column 0 {Result ID}]
set headerRow [lindex $f1 0 1]

set f2 [m search -glob rect 0 $headerRow 0 [expr {[m rows] - 1}] { These*}]
set numofRow [lindex $f2 0 1]

set headercol1 [m search row $headerRow { Horizontal-1 Acc. Filename}]
set headercol2 [m search row $headerRow { Horizontal-2 Acc. Filename}]  

set indexheaderH1col [lindex $headercol1  0 0]
set indexheaderH2col [lindex $headercol2  0 0]

set rows [m get rect $indexheaderH1col [expr {$headerRow+1}] $indexheaderH2col [expr {$numofRow-1}]]

set rows [lmap row $rows {
    lassign $row a b
    list [string trim $a] [string trim $b]
}]

foreach row $rows {
    puts [format {%-30s   %s} {*}$row]
}

puts [format {Vector=[ %s ]} [concat {*}$rows]]

Comments:

• You don't need to set the number of columns if you use read2matrix with auto
• In this file, there is no empty cell after the table. Instead, we need to search for a string beginning with " These"
• Since each cell holds a space character followed by the value, we need to trim off space around the value, otherwise the concatenation will go wrong. The part with the lmap command fixes that
• Always brace your expressions

Documentation: + (operator) , - (operator) , < (operator) , chan , close , concat , csv (package) , expr , for , format , incr , lassign , lindex , lmap (for Tcl 8.5) , lmap , open , package , puts , set , struct::matrix (package) , {*} (syntax)

Answer 2

wipe all

package require csv
package require struct::matrix

::struct::matrix m
m add columns 2

set chan [open _SearchResults.csv]
::csv::read2matrix $chan m  , auto
close $chan

set f1 [m search column 0 {Result ID}]
set headerRow [lindex $f1 0 1]

set f2 [m search rect 0 $headerRow 0 [expr {[m rows] - 1}] {}]
set  numofRow [lindex [lindex $f2 0 1]]

set headercol1 [m search row  $headerRow { Horizontal-1 Acc. Filename}]
set headercol2 [m search row  $headerRow  { Horizontal-2 Acc. Filename}]  

set indexheaderH1col [lindex $headercol1  0 0]
set indexheaderH2col [lindex $headercol2  0 0]

set header1 [m get cell $indexheaderH1col $headerRow]
set header2 [m get cell $indexheaderH2col $headerRow]

for {set r [expr $headerRow+1]} {$r < [expr $numofRow-1]} {incr r} {
    puts [format {%-30s   %s}  [m get cell $indexheaderH1col $r]  [m get cell $indexheaderH2col $r]]
}

set  vector   [concat {*}[m get rect $indexheaderH1col  [expr $headerRow+1] $indexheaderH2col [expr $numofRow-1]]]

puts [format {Vector=[ %s ]} [concat {*}[m get rect $indexheaderH1col  [expr $headerRow+1] $indexheaderH2col [expr $numofRow-1]]]]