diff options
Diffstat (limited to 'Doc')
| -rw-r--r-- | Doc/lib/libcsv.tex | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/Doc/lib/libcsv.tex b/Doc/lib/libcsv.tex index e2877ee..bf8b0bf 100644 --- a/Doc/lib/libcsv.tex +++ b/Doc/lib/libcsv.tex @@ -117,14 +117,18 @@ Return the names of all registered dialects. The \module{csv} module defines the following classes: -\begin{classdesc}{DictReader}{csvfile, fieldnames\optional{, +\begin{classdesc}{DictReader}{csvfile\optional{, + fieldnames=\constant{None},\optional{, restkey=\constant{None}\optional{, restval=\constant{None}\optional{, dialect=\code{'excel'}\optional{, - fmtparam}}}}} + fmtparam}}}}}} Create an object which operates like a regular reader but maps the -information read into a dict whose keys are given by the \var{fieldnames} -parameter. If the row read has fewer fields than the fieldnames sequence, +information read into a dict whose keys are given by the optional +{} \var{fieldnames} +parameter. If the \var{fieldnames} parameter is omitted, the values in +the first row of the \var{csvfile} will be used as the fieldnames. +If the row read has fewer fields than the fieldnames sequence, the value of \var{restval} will be used as the default value. If the row read has more fields than the fieldnames sequence, the remaining data is added as a sequence keyed by the value of \var{restkey}. If the row read @@ -149,6 +153,13 @@ method contains a key not found in \var{fieldnames}, the optional to \code{'raise'} a \exception{ValueError} is raised. If it is set to \code{'ignore'}, extra values in the dictionary are ignored. All other parameters are interpreted as for \class{writer} objects. + +Note that unlike the \class{DictReader} class, the \var{fieldnames} +parameter of the \class{DictWriter} is not optional. Since Python's +\class{dict} objects are not ordered, there is not enough information +available to deduce the order in which the row should be written to the +\var{csvfile}. + \end{classdesc} \begin{classdesc*}{Dialect}{} |