1csv(n) CSV processing csv(n)
2______________________________________________________________________________
6
8 csv - Procedures to handle CSV data.
9
11 package require Tcl 8.4
12 package require csv ?0.8.1?
14 ::csv::iscomplete data
16 ::csv::join values ?sepChar? ?delChar? ?delMode?
18 ::csv::joinlist values ?sepChar? ?delChar? ?delMode?
20 ::csv::joinmatrix matrix ?sepChar? ?delChar? ?delMode?
22 ::csv::read2matrix ?-alternate? chan m {sepChar ,} {expand none}
24 ::csv::read2queue ?-alternate? chan q {sepChar ,}
26 ::csv::report cmd matrix ?chan?
28 ::csv::split ?-alternate? line ?sepChar? ?delChar?
30 ::csv::split2matrix ?-alternate? m line {sepChar ,} {expand none}
32 ::csv::split2queue ?-alternate? q line {sepChar ,}
34 ::csv::writematrix m chan ?sepChar? ?delChar?
36 ::csv::writequeue q chan ?sepChar? ?delChar?
38______________________________________________________________________________
40
42 The csv package provides commands to manipulate information in CSV FOR‐
43 MAT (CSV = Comma Separated Values).
44
46 The following commands are available:
47 ::csv::iscomplete data
49 A predicate checking if the argument data is a complete csv
50 record. The result is a boolean flag indicating the completeness
51 of the data. The result is true if the data is complete.
52 ::csv::join values ?sepChar? ?delChar? ?delMode?
54 Takes a list of values and returns a string in CSV format con‐
55 taining these values. The separator character can be defined by
56 the caller, but this is optional. The default is ",". The quot‐
57 ing aka delimiting character can be defined by the caller, but
58 this is optional. The default is '"'. By default the quoting
59 mode delMode is "auto", surrounding values with delChar only
60 when needed. When set to "always" however, values are always
61 surrounded by the delChar instead.
62 ::csv::joinlist values ?sepChar? ?delChar? ?delMode?
64 Takes a list of lists of values and returns a string in CSV for‐
65 mat containing these values. The separator character can be
66 defined by the caller, but this is optional. The default is ",".
67 The quoting character can be defined by the caller, but this is
68 optional. The default is '"'. By default the quoting mode
69 delMode is "auto", surrounding values with delChar only when
70 needed. When set to "always" however, values are always sur‐
71 rounded by the delChar instead. Each element of the outer list
72 is considered a record, these are separated by newlines in the
73 result. The elements of each record are formatted as usual (via
74 ::csv::join).
75 ::csv::joinmatrix matrix ?sepChar? ?delChar? ?delMode?
77 Takes a matrix object following the API specified for the
78 struct::matrix package and returns a string in CSV format con‐
79 taining these values. The separator character can be defined by
80 the caller, but this is optional. The default is ",". The quot‐
81 ing character can be defined by the caller, but this is
82 optional. The default is ´"'. By default the quoting mode
83 delMode is "auto", surrounding values with delChar only when
84 needed. When set to "always" however, values are always sur‐
85 rounded by the delChar instead. Each row of the matrix is con‐
86 sidered a record, these are separated by newlines in the result.
87 The elements of each record are formatted as usual (via
88 ::csv::join).
89 ::csv::read2matrix ?-alternate? chan m {sepChar ,} {expand none}
91 A wrapper around ::csv::split2matrix (see below) reading CSV-
92 formatted lines from the specified channel (until EOF) and
93 adding them to the given matrix. For an explanation of the
94 expand argument see ::csv::split2matrix.
95 ::csv::read2queue ?-alternate? chan q {sepChar ,}
97 A wrapper around ::csv::split2queue (see below) reading CSV-for‐
98 matted lines from the specified channel (until EOF) and adding
99 them to the given queue.
100 ::csv::report cmd matrix ?chan?
102 A report command which can be used by the matrix methods format
103 2string and format 2chan. For the latter this command delegates
104 the work to ::csv::writematrix. cmd is expected to be either
105 printmatrix or printmatrix2channel. The channel argument, chan,
106 has to be present for the latter and must not be present for the
107 first.
108 ::csv::split ?-alternate? line ?sepChar? ?delChar?
110 converts a line in CSV format into a list of the values con‐
111 tained in the line. The character used to separate the values
112 from each other can be defined by the caller, via sepChar, but
113 this is optional. The default is ",". The quoting character can
114 be defined by the caller, but this is optional. The default is
115 '"'.
116 If the option -alternate is specified a slightly different syn‐
118 tax is used to parse the input. This syntax is explained below,
119 in the section FORMAT.
120 ::csv::split2matrix ?-alternate? m line {sepChar ,} {expand none}
122 The same as ::csv::split, but appends the resulting list as a
123 new row to the matrix m, using the method add row. The expansion
124 mode specified via expand determines how the command handles a
125 matrix with less columns than contained in line. The allowed
126 modes are:
127 none This is the default mode. In this mode it is the respon‐
129 sibility of the caller to ensure that the matrix has
130 enough columns to contain the full line. If there are not
131 enough columns the list of values is silently truncated
132 at the end to fit.
133 empty In this mode the command expands an empty matrix to hold
135 all columns of the specified line, but goes no further.
136 The overall effect is that the first of a series of lines
137 determines the number of columns in the matrix and all
138 following lines are truncated to that size, as if mode
139 none was set.
140 auto In this mode the command expands the matrix as needed to
142 hold all columns contained in line. The overall effect is
143 that after adding a series of lines the matrix will have
144 enough columns to hold all columns of the longest line
145 encountered so far.
146 ::csv::split2queue ?-alternate? q line {sepChar ,}
148 The same as ::csv::split, but appending the resulting list as a
149 single item to the queue q, using the method put.
150 ::csv::writematrix m chan ?sepChar? ?delChar?
152 A wrapper around ::csv::join taking all rows in the matrix m and
153 writing them CSV formatted into the channel chan.
154 ::csv::writequeue q chan ?sepChar? ?delChar?
156 A wrapper around ::csv::join taking all items in the queue q
157 (assumes that they are lists) and writing them CSV formatted
158 into the channel chan.
159
161 The format of regular CSV files is specified as
162 [1] Each record of a csv file (comma-separated values, as exported
164 e.g. by Excel) is a set of ASCII values separated by ",". For
165 other languages it may be ";" however, although this is not
166 important for this case as the functions provided here allow any
167 separator character.
168 [2] If and only if a value contains itself the separator ",", then
170 it (the value) has to be put between "". If the value does not
171 contain the separator character then quoting is optional.
172 [3] If a value contains the character ", that character is repre‐
174 sented by "".
175 [4] The output string "" represents the value ". In other words, it
177 is assumed that it was created through rule 3, and only this
178 rule, i.e. that the value was not quoted.
179 An alternate format definition mainly used by MS products specifies
181 that the output string "" is a representation of the empty string. In
182 other words, it is assumed that the output was generated out of the
183 empty string by quoting it (i.e. rule 2), and not through rule 3. This
184 is the only difference between the regular and the alternate format.
185 The alternate format is activated through specification of the option
187 -alternate to the various split commands.
188
190 Using the regular format the record
191 123,"123,521.2","Mary says ""Hello, I am Mary""",""
193 is parsed into the items
196 a) 123
198 b) 123,521.2
199 c) Mary says "Hello, I am Mary"
200 d) "
201 Using the alternate format the result is
204 a) 123
206 b) 123,521.2
207 c) Mary says "Hello, I am Mary"
208 d) (the empty string)
209 instead. As can be seen only item (d) is different, now the empty
211 string instead of a ".
212
214 This document, and the package it describes, will undoubtedly contain
215 bugs and other problems. Please report such in the category csv of the
216 Tcllib Trackers [http://core.tcl.tk/tcllib/reportlist]. Please also
217 report any ideas for enhancements you may have for either package
218 and/or documentation.
219 When proposing code changes, please provide unified diffs, i.e the out‐
221 put of diff -u.
222 Note further that attachments are strongly preferred over inlined
224 patches. Attachments can be made by going to the Edit form of the
225 ticket immediately after its creation, and then using the left-most
226 button in the secondary navigation bar.
227
229 matrix, queue
230
232 csv, matrix, package, queue, tcllib
233
235 Text processing
236
238 Copyright (c) 2002-2015 Andreas Kupries <andreas_kupries@users.sourceforge.net>
239tcllib 0.8.1 csv(n)