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| |
| <h1>Read a CSV or other delimited file with Arrow</h1> |
| <small class="dont-index">Source: <a href="https://github.com/apache/arrow/blob/main/r/R/csv.R" class="external-link"><code>R/csv.R</code></a></small> |
| <div class="d-none name"><code>read_delim_arrow.Rd</code></div> |
| </div> |
| |
| <div class="ref-description section level2"> |
| <p>These functions uses the Arrow C++ CSV reader to read into a <code>tibble</code>. |
| Arrow C++ options have been mapped to argument names that follow those of |
| <code>readr::read_delim()</code>, and <code>col_select</code> was inspired by <code>vroom::vroom()</code>.</p> |
| </div> |
| |
| <div class="section level2"> |
| <h2 id="ref-usage">Usage<a class="anchor" aria-label="anchor" href="#ref-usage"></a></h2> |
| <div class="sourceCode"><pre class="sourceCode r"><code><span><span class="fu">read_delim_arrow</span><span class="op">(</span></span> |
| <span> <span class="va">file</span>,</span> |
| <span> delim <span class="op">=</span> <span class="st">","</span>,</span> |
| <span> quote <span class="op">=</span> <span class="st">"\""</span>,</span> |
| <span> escape_double <span class="op">=</span> <span class="cn">TRUE</span>,</span> |
| <span> escape_backslash <span class="op">=</span> <span class="cn">FALSE</span>,</span> |
| <span> schema <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> col_names <span class="op">=</span> <span class="cn">TRUE</span>,</span> |
| <span> col_types <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> col_select <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> na <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="st">""</span>, <span class="st">"NA"</span><span class="op">)</span>,</span> |
| <span> quoted_na <span class="op">=</span> <span class="cn">TRUE</span>,</span> |
| <span> skip_empty_rows <span class="op">=</span> <span class="cn">TRUE</span>,</span> |
| <span> skip <span class="op">=</span> <span class="fl">0L</span>,</span> |
| <span> parse_options <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> convert_options <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> read_options <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> as_data_frame <span class="op">=</span> <span class="cn">TRUE</span>,</span> |
| <span> timestamp_parsers <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> decimal_point <span class="op">=</span> <span class="st">"."</span></span> |
| <span><span class="op">)</span></span> |
| <span></span> |
| <span><span class="fu">read_csv_arrow</span><span class="op">(</span></span> |
| <span> <span class="va">file</span>,</span> |
| <span> quote <span class="op">=</span> <span class="st">"\""</span>,</span> |
| <span> escape_double <span class="op">=</span> <span class="cn">TRUE</span>,</span> |
| <span> escape_backslash <span class="op">=</span> <span class="cn">FALSE</span>,</span> |
| <span> schema <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> col_names <span class="op">=</span> <span class="cn">TRUE</span>,</span> |
| <span> col_types <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> col_select <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> na <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="st">""</span>, <span class="st">"NA"</span><span class="op">)</span>,</span> |
| <span> quoted_na <span class="op">=</span> <span class="cn">TRUE</span>,</span> |
| <span> skip_empty_rows <span class="op">=</span> <span class="cn">TRUE</span>,</span> |
| <span> skip <span class="op">=</span> <span class="fl">0L</span>,</span> |
| <span> parse_options <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> convert_options <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> read_options <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> as_data_frame <span class="op">=</span> <span class="cn">TRUE</span>,</span> |
| <span> timestamp_parsers <span class="op">=</span> <span class="cn">NULL</span></span> |
| <span><span class="op">)</span></span> |
| <span></span> |
| <span><span class="fu">read_csv2_arrow</span><span class="op">(</span></span> |
| <span> <span class="va">file</span>,</span> |
| <span> quote <span class="op">=</span> <span class="st">"\""</span>,</span> |
| <span> escape_double <span class="op">=</span> <span class="cn">TRUE</span>,</span> |
| <span> escape_backslash <span class="op">=</span> <span class="cn">FALSE</span>,</span> |
| <span> schema <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> col_names <span class="op">=</span> <span class="cn">TRUE</span>,</span> |
| <span> col_types <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> col_select <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> na <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="st">""</span>, <span class="st">"NA"</span><span class="op">)</span>,</span> |
| <span> quoted_na <span class="op">=</span> <span class="cn">TRUE</span>,</span> |
| <span> skip_empty_rows <span class="op">=</span> <span class="cn">TRUE</span>,</span> |
| <span> skip <span class="op">=</span> <span class="fl">0L</span>,</span> |
| <span> parse_options <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> convert_options <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> read_options <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> as_data_frame <span class="op">=</span> <span class="cn">TRUE</span>,</span> |
| <span> timestamp_parsers <span class="op">=</span> <span class="cn">NULL</span></span> |
| <span><span class="op">)</span></span> |
| <span></span> |
| <span><span class="fu">read_tsv_arrow</span><span class="op">(</span></span> |
| <span> <span class="va">file</span>,</span> |
| <span> quote <span class="op">=</span> <span class="st">"\""</span>,</span> |
| <span> escape_double <span class="op">=</span> <span class="cn">TRUE</span>,</span> |
| <span> escape_backslash <span class="op">=</span> <span class="cn">FALSE</span>,</span> |
| <span> schema <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> col_names <span class="op">=</span> <span class="cn">TRUE</span>,</span> |
| <span> col_types <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> col_select <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> na <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="st">""</span>, <span class="st">"NA"</span><span class="op">)</span>,</span> |
| <span> quoted_na <span class="op">=</span> <span class="cn">TRUE</span>,</span> |
| <span> skip_empty_rows <span class="op">=</span> <span class="cn">TRUE</span>,</span> |
| <span> skip <span class="op">=</span> <span class="fl">0L</span>,</span> |
| <span> parse_options <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> convert_options <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> read_options <span class="op">=</span> <span class="cn">NULL</span>,</span> |
| <span> as_data_frame <span class="op">=</span> <span class="cn">TRUE</span>,</span> |
| <span> timestamp_parsers <span class="op">=</span> <span class="cn">NULL</span></span> |
| <span><span class="op">)</span></span></code></pre></div> |
| </div> |
| |
| <div class="section level2"> |
| <h2 id="arguments">Arguments<a class="anchor" aria-label="anchor" href="#arguments"></a></h2> |
| |
| |
| <dl><dt id="arg-file">file<a class="anchor" aria-label="anchor" href="#arg-file"></a></dt> |
| <dd><p>A character file name or URI, connection, literal data (either a |
| single string or a <a href="https://rdrr.io/r/base/raw.html" class="external-link">raw</a> vector), an Arrow input stream, or a <code>FileSystem</code> |
| with path (<code>SubTreeFileSystem</code>).</p> |
| <p>If a file name, a memory-mapped Arrow <a href="InputStream.html">InputStream</a> will be opened and |
| closed when finished; compression will be detected from the file extension |
| and handled automatically. If an input stream is provided, it will be left |
| open.</p> |
| <p>To be recognised as literal data, the input must be wrapped with <code><a href="https://rdrr.io/r/base/AsIs.html" class="external-link">I()</a></code>.</p></dd> |
| |
| |
| <dt id="arg-delim">delim<a class="anchor" aria-label="anchor" href="#arg-delim"></a></dt> |
| <dd><p>Single character used to separate fields within a record.</p></dd> |
| |
| |
| <dt id="arg-quote">quote<a class="anchor" aria-label="anchor" href="#arg-quote"></a></dt> |
| <dd><p>Single character used to quote strings.</p></dd> |
| |
| |
| <dt id="arg-escape-double">escape_double<a class="anchor" aria-label="anchor" href="#arg-escape-double"></a></dt> |
| <dd><p>Does the file escape quotes by doubling them? |
| i.e. If this option is <code>TRUE</code>, the value <code>""""</code> represents |
| a single quote, <code>\"</code>.</p></dd> |
| |
| |
| <dt id="arg-escape-backslash">escape_backslash<a class="anchor" aria-label="anchor" href="#arg-escape-backslash"></a></dt> |
| <dd><p>Does the file use backslashes to escape special |
| characters? This is more general than <code>escape_double</code> as backslashes |
| can be used to escape the delimiter character, the quote character, or |
| to add special characters like <code>\\n</code>.</p></dd> |
| |
| |
| <dt id="arg-schema">schema<a class="anchor" aria-label="anchor" href="#arg-schema"></a></dt> |
| <dd><p><a href="Schema-class.html">Schema</a> that describes the table. If provided, it will be |
| used to satisfy both <code>col_names</code> and <code>col_types</code>.</p></dd> |
| |
| |
| <dt id="arg-col-names">col_names<a class="anchor" aria-label="anchor" href="#arg-col-names"></a></dt> |
| <dd><p>If <code>TRUE</code>, the first row of the input will be used as the |
| column names and will not be included in the data frame. If <code>FALSE</code>, column |
| names will be generated by Arrow, starting with "f0", "f1", ..., "fN". |
| Alternatively, you can specify a character vector of column names.</p></dd> |
| |
| |
| <dt id="arg-col-types">col_types<a class="anchor" aria-label="anchor" href="#arg-col-types"></a></dt> |
| <dd><p>A compact string representation of the column types, |
| an Arrow <a href="Schema-class.html">Schema</a>, or <code>NULL</code> (the default) to infer types from the data.</p></dd> |
| |
| |
| <dt id="arg-col-select">col_select<a class="anchor" aria-label="anchor" href="#arg-col-select"></a></dt> |
| <dd><p>A character vector of column names to keep, as in the |
| "select" argument to <code>data.table::fread()</code>, or a |
| <a href="https://tidyselect.r-lib.org/reference/eval_select.html" class="external-link">tidy selection specification</a> |
| of columns, as used in <code><a href="https://dplyr.tidyverse.org/reference/select.html" class="external-link">dplyr::select()</a></code>.</p></dd> |
| |
| |
| <dt id="arg-na">na<a class="anchor" aria-label="anchor" href="#arg-na"></a></dt> |
| <dd><p>A character vector of strings to interpret as missing values.</p></dd> |
| |
| |
| <dt id="arg-quoted-na">quoted_na<a class="anchor" aria-label="anchor" href="#arg-quoted-na"></a></dt> |
| <dd><p>Should missing values inside quotes be treated as missing |
| values (the default) or strings. (Note that this is different from the |
| the Arrow C++ default for the corresponding convert option, |
| <code>strings_can_be_null</code>.)</p></dd> |
| |
| |
| <dt id="arg-skip-empty-rows">skip_empty_rows<a class="anchor" aria-label="anchor" href="#arg-skip-empty-rows"></a></dt> |
| <dd><p>Should blank rows be ignored altogether? If |
| <code>TRUE</code>, blank rows will not be represented at all. If <code>FALSE</code>, they will be |
| filled with missings.</p></dd> |
| |
| |
| <dt id="arg-skip">skip<a class="anchor" aria-label="anchor" href="#arg-skip"></a></dt> |
| <dd><p>Number of lines to skip before reading data.</p></dd> |
| |
| |
| <dt id="arg-parse-options">parse_options<a class="anchor" aria-label="anchor" href="#arg-parse-options"></a></dt> |
| <dd><p>see <a href="csv_parse_options.html">CSV parsing options</a>. |
| If given, this overrides any |
| parsing options provided in other arguments (e.g. <code>delim</code>, <code>quote</code>, etc.).</p></dd> |
| |
| |
| <dt id="arg-convert-options">convert_options<a class="anchor" aria-label="anchor" href="#arg-convert-options"></a></dt> |
| <dd><p>see <a href="csv_convert_options.html">CSV conversion options</a></p></dd> |
| |
| |
| <dt id="arg-read-options">read_options<a class="anchor" aria-label="anchor" href="#arg-read-options"></a></dt> |
| <dd><p>see <a href="csv_read_options.html">CSV reading options</a></p></dd> |
| |
| |
| <dt id="arg-as-data-frame">as_data_frame<a class="anchor" aria-label="anchor" href="#arg-as-data-frame"></a></dt> |
| <dd><p>Should the function return a <code>tibble</code> (default) or |
| an Arrow <a href="Table-class.html">Table</a>?</p></dd> |
| |
| |
| <dt id="arg-timestamp-parsers">timestamp_parsers<a class="anchor" aria-label="anchor" href="#arg-timestamp-parsers"></a></dt> |
| <dd><p>User-defined timestamp parsers. If more than one |
| parser is specified, the CSV conversion logic will try parsing values |
| starting from the beginning of this vector. Possible values are:</p><ul><li><p><code>NULL</code>: the default, which uses the ISO-8601 parser</p></li> |
| <li><p>a character vector of <a href="https://rdrr.io/r/base/strptime.html" class="external-link">strptime</a> parse strings</p></li> |
| <li><p>a list of <a href="CsvReadOptions.html">TimestampParser</a> objects</p></li> |
| </ul></dd> |
| |
| |
| <dt id="arg-decimal-point">decimal_point<a class="anchor" aria-label="anchor" href="#arg-decimal-point"></a></dt> |
| <dd><p>Character to use for decimal point in floating point numbers.</p></dd> |
| |
| </dl></div> |
| <div class="section level2"> |
| <h2 id="value">Value<a class="anchor" aria-label="anchor" href="#value"></a></h2> |
| <p>A <code>tibble</code>, or a Table if <code>as_data_frame = FALSE</code>.</p> |
| </div> |
| <div class="section level2"> |
| <h2 id="details">Details<a class="anchor" aria-label="anchor" href="#details"></a></h2> |
| <p><code>read_csv_arrow()</code> and <code>read_tsv_arrow()</code> are wrappers around |
| <code>read_delim_arrow()</code> that specify a delimiter. <code>read_csv2_arrow()</code> uses <code>;</code> for |
| the delimiter and <code>,</code> for the decimal point.</p> |
| <p>Note that not all <code>readr</code> options are currently implemented here. Please file |
| an issue if you encounter one that <code>arrow</code> should support.</p> |
| <p>If you need to control Arrow-specific reader parameters that don't have an |
| equivalent in <code>readr::read_csv()</code>, you can either provide them in the |
| <code>parse_options</code>, <code>convert_options</code>, or <code>read_options</code> arguments, or you can |
| use <a href="CsvTableReader.html">CsvTableReader</a> directly for lower-level access.</p> |
| </div> |
| <div class="section level2"> |
| <h2 id="specifying-column-types-and-names">Specifying column types and names<a class="anchor" aria-label="anchor" href="#specifying-column-types-and-names"></a></h2> |
| |
| |
| |
| <p>By default, the CSV reader will infer the column names and data types from the file, but there |
| are a few ways you can specify them directly.</p> |
| <p>One way is to provide an Arrow <a href="Schema-class.html">Schema</a> in the <code>schema</code> argument, |
| which is an ordered map of column name to type. |
| When provided, it satisfies both the <code>col_names</code> and <code>col_types</code> arguments. |
| This is good if you know all of this information up front.</p> |
| <p>You can also pass a <code>Schema</code> to the <code>col_types</code> argument. If you do this, |
| column names will still be inferred from the file unless you also specify |
| <code>col_names</code>. In either case, the column names in the <code>Schema</code> must match the |
| data's column names, whether they are explicitly provided or inferred. That |
| said, this <code>Schema</code> does not have to reference all columns: those omitted |
| will have their types inferred.</p> |
| <p>Alternatively, you can declare column types by providing the compact string representation |
| that <code>readr</code> uses to the <code>col_types</code> argument. This means you provide a |
| single string, one character per column, where the characters map to Arrow |
| types analogously to the <code>readr</code> type mapping:</p><ul><li><p>"c": <code><a href="data-type.html">utf8()</a></code></p></li> |
| <li><p>"i": <code><a href="data-type.html">int32()</a></code></p></li> |
| <li><p>"n": <code><a href="data-type.html">float64()</a></code></p></li> |
| <li><p>"d": <code><a href="data-type.html">float64()</a></code></p></li> |
| <li><p>"l": <code><a href="data-type.html">bool()</a></code></p></li> |
| <li><p>"f": <code><a href="dictionary.html">dictionary()</a></code></p></li> |
| <li><p>"D": <code><a href="data-type.html">date32()</a></code></p></li> |
| <li><p>"T": <code><a href="data-type.html">timestamp(unit = "ns")</a></code></p></li> |
| <li><p>"t": <code><a href="data-type.html">time32()</a></code> (The <code>unit</code> arg is set to the default value <code>"ms"</code>)</p></li> |
| <li><p>"_": <code><a href="data-type.html">null()</a></code></p></li> |
| <li><p>"-": <code><a href="data-type.html">null()</a></code></p></li> |
| <li><p>"?": infer the type from the data</p></li> |
| </ul><p>If you use the compact string representation for <code>col_types</code>, you must also |
| specify <code>col_names</code>.</p> |
| <p>Regardless of how types are specified, all columns with a <code><a href="data-type.html">null()</a></code> type will |
| be dropped.</p> |
| <p>Note that if you are specifying column names, whether by <code>schema</code> or |
| <code>col_names</code>, and the CSV file has a header row that would otherwise be used |
| to identify column names, you'll need to add <code>skip = 1</code> to skip that row.</p> |
| </div> |
| |
| <div class="section level2"> |
| <h2 id="ref-examples">Examples<a class="anchor" aria-label="anchor" href="#ref-examples"></a></h2> |
| <div class="sourceCode"><pre class="sourceCode r"><code><span class="r-in"><span><span class="va">tf</span> <span class="op"><-</span> <span class="fu"><a href="https://rdrr.io/r/base/tempfile.html" class="external-link">tempfile</a></span><span class="op">(</span><span class="op">)</span></span></span> |
| <span class="r-in"><span><span class="fu"><a href="https://rdrr.io/r/base/on.exit.html" class="external-link">on.exit</a></span><span class="op">(</span><span class="fu"><a href="https://rdrr.io/r/base/unlink.html" class="external-link">unlink</a></span><span class="op">(</span><span class="va">tf</span><span class="op">)</span><span class="op">)</span></span></span> |
| <span class="r-in"><span><span class="fu"><a href="https://rdrr.io/r/utils/write.table.html" class="external-link">write.csv</a></span><span class="op">(</span><span class="va">mtcars</span>, file <span class="op">=</span> <span class="va">tf</span><span class="op">)</span></span></span> |
| <span class="r-in"><span><span class="va">df</span> <span class="op"><-</span> <span class="fu">read_csv_arrow</span><span class="op">(</span><span class="va">tf</span><span class="op">)</span></span></span> |
| <span class="r-in"><span><span class="fu"><a href="https://rdrr.io/r/base/dim.html" class="external-link">dim</a></span><span class="op">(</span><span class="va">df</span><span class="op">)</span></span></span> |
| <span class="r-out co"><span class="r-pr">#></span> [1] 32 12</span> |
| <span class="r-in"><span><span class="co"># Can select columns</span></span></span> |
| <span class="r-in"><span><span class="va">df</span> <span class="op"><-</span> <span class="fu">read_csv_arrow</span><span class="op">(</span><span class="va">tf</span>, col_select <span class="op">=</span> <span class="fu"><a href="https://tidyselect.r-lib.org/reference/starts_with.html" class="external-link">starts_with</a></span><span class="op">(</span><span class="st">"d"</span><span class="op">)</span><span class="op">)</span></span></span> |
| <span class="r-in"><span></span></span> |
| <span class="r-in"><span><span class="co"># Specifying column types and names</span></span></span> |
| <span class="r-in"><span><span class="fu"><a href="https://rdrr.io/r/utils/write.table.html" class="external-link">write.csv</a></span><span class="op">(</span><span class="fu"><a href="https://rdrr.io/r/base/data.frame.html" class="external-link">data.frame</a></span><span class="op">(</span>x <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="fl">1</span>, <span class="fl">3</span><span class="op">)</span>, y <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="fl">2</span>, <span class="fl">4</span><span class="op">)</span><span class="op">)</span>, file <span class="op">=</span> <span class="va">tf</span>, row.names <span class="op">=</span> <span class="cn">FALSE</span><span class="op">)</span></span></span> |
| <span class="r-in"><span><span class="fu">read_csv_arrow</span><span class="op">(</span><span class="va">tf</span>, schema <span class="op">=</span> <span class="fu"><a href="schema.html">schema</a></span><span class="op">(</span>x <span class="op">=</span> <span class="fu"><a href="data-type.html">int32</a></span><span class="op">(</span><span class="op">)</span>, y <span class="op">=</span> <span class="fu"><a href="data-type.html">utf8</a></span><span class="op">(</span><span class="op">)</span><span class="op">)</span>, skip <span class="op">=</span> <span class="fl">1</span><span class="op">)</span></span></span> |
| <span class="r-out co"><span class="r-pr">#></span> <span style="color: #949494;"># A tibble: 2 x 2</span></span> |
| <span class="r-out co"><span class="r-pr">#></span> x y </span> |
| <span class="r-out co"><span class="r-pr">#></span> <span style="color: #949494; font-style: italic;"><int></span> <span style="color: #949494; font-style: italic;"><chr></span></span> |
| <span class="r-out co"><span class="r-pr">#></span> <span style="color: #BCBCBC;">1</span> 1 2 </span> |
| <span class="r-out co"><span class="r-pr">#></span> <span style="color: #BCBCBC;">2</span> 3 4 </span> |
| <span class="r-in"><span><span class="fu">read_csv_arrow</span><span class="op">(</span><span class="va">tf</span>, col_types <span class="op">=</span> <span class="fu"><a href="schema.html">schema</a></span><span class="op">(</span>y <span class="op">=</span> <span class="fu"><a href="data-type.html">utf8</a></span><span class="op">(</span><span class="op">)</span><span class="op">)</span><span class="op">)</span></span></span> |
| <span class="r-out co"><span class="r-pr">#></span> <span style="color: #949494;"># A tibble: 2 x 2</span></span> |
| <span class="r-out co"><span class="r-pr">#></span> x y </span> |
| <span class="r-out co"><span class="r-pr">#></span> <span style="color: #949494; font-style: italic;"><int></span> <span style="color: #949494; font-style: italic;"><chr></span></span> |
| <span class="r-out co"><span class="r-pr">#></span> <span style="color: #BCBCBC;">1</span> 1 2 </span> |
| <span class="r-out co"><span class="r-pr">#></span> <span style="color: #BCBCBC;">2</span> 3 4 </span> |
| <span class="r-in"><span><span class="fu">read_csv_arrow</span><span class="op">(</span><span class="va">tf</span>, col_types <span class="op">=</span> <span class="st">"ic"</span>, col_names <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="st">"x"</span>, <span class="st">"y"</span><span class="op">)</span>, skip <span class="op">=</span> <span class="fl">1</span><span class="op">)</span></span></span> |
| <span class="r-out co"><span class="r-pr">#></span> <span style="color: #949494;"># A tibble: 2 x 2</span></span> |
| <span class="r-out co"><span class="r-pr">#></span> x y </span> |
| <span class="r-out co"><span class="r-pr">#></span> <span style="color: #949494; font-style: italic;"><int></span> <span style="color: #949494; font-style: italic;"><chr></span></span> |
| <span class="r-out co"><span class="r-pr">#></span> <span style="color: #BCBCBC;">1</span> 1 2 </span> |
| <span class="r-out co"><span class="r-pr">#></span> <span style="color: #BCBCBC;">2</span> 3 4 </span> |
| <span class="r-in"><span></span></span> |
| <span class="r-in"><span><span class="co"># Note that if a timestamp column contains time zones,</span></span></span> |
| <span class="r-in"><span><span class="co"># the string "T" `col_types` specification won't work.</span></span></span> |
| <span class="r-in"><span><span class="co"># To parse timestamps with time zones, provide a [Schema] to `col_types`</span></span></span> |
| <span class="r-in"><span><span class="co"># and specify the time zone in the type object:</span></span></span> |
| <span class="r-in"><span><span class="va">tf</span> <span class="op"><-</span> <span class="fu"><a href="https://rdrr.io/r/base/tempfile.html" class="external-link">tempfile</a></span><span class="op">(</span><span class="op">)</span></span></span> |
| <span class="r-in"><span><span class="fu"><a href="https://rdrr.io/r/utils/write.table.html" class="external-link">write.csv</a></span><span class="op">(</span><span class="fu"><a href="https://rdrr.io/r/base/data.frame.html" class="external-link">data.frame</a></span><span class="op">(</span>x <span class="op">=</span> <span class="st">"1970-01-01T12:00:00+12:00"</span><span class="op">)</span>, file <span class="op">=</span> <span class="va">tf</span>, row.names <span class="op">=</span> <span class="cn">FALSE</span><span class="op">)</span></span></span> |
| <span class="r-in"><span><span class="fu">read_csv_arrow</span><span class="op">(</span></span></span> |
| <span class="r-in"><span> <span class="va">tf</span>,</span></span> |
| <span class="r-in"><span> col_types <span class="op">=</span> <span class="fu"><a href="schema.html">schema</a></span><span class="op">(</span>x <span class="op">=</span> <span class="fu"><a href="data-type.html">timestamp</a></span><span class="op">(</span>unit <span class="op">=</span> <span class="st">"us"</span>, timezone <span class="op">=</span> <span class="st">"UTC"</span><span class="op">)</span><span class="op">)</span></span></span> |
| <span class="r-in"><span><span class="op">)</span></span></span> |
| <span class="r-out co"><span class="r-pr">#></span> <span style="color: #949494;"># A tibble: 1 x 1</span></span> |
| <span class="r-out co"><span class="r-pr">#></span> x </span> |
| <span class="r-out co"><span class="r-pr">#></span> <span style="color: #949494; font-style: italic;"><dttm></span> </span> |
| <span class="r-out co"><span class="r-pr">#></span> <span style="color: #BCBCBC;">1</span> 1970-01-01 <span style="color: #949494;">00:00:00</span></span> |
| <span class="r-in"><span></span></span> |
| <span class="r-in"><span><span class="co"># Read directly from strings with `I()`</span></span></span> |
| <span class="r-in"><span><span class="fu">read_csv_arrow</span><span class="op">(</span><span class="fu"><a href="https://rdrr.io/r/base/AsIs.html" class="external-link">I</a></span><span class="op">(</span><span class="st">"x,y\n1,2\n3,4"</span><span class="op">)</span><span class="op">)</span></span></span> |
| <span class="r-out co"><span class="r-pr">#></span> <span style="color: #949494;"># A tibble: 2 x 2</span></span> |
| <span class="r-out co"><span class="r-pr">#></span> x y</span> |
| <span class="r-out co"><span class="r-pr">#></span> <span style="color: #949494; font-style: italic;"><int></span> <span style="color: #949494; font-style: italic;"><int></span></span> |
| <span class="r-out co"><span class="r-pr">#></span> <span style="color: #BCBCBC;">1</span> 1 2</span> |
| <span class="r-out co"><span class="r-pr">#></span> <span style="color: #BCBCBC;">2</span> 3 4</span> |
| <span class="r-in"><span><span class="fu">read_delim_arrow</span><span class="op">(</span><span class="fu"><a href="https://rdrr.io/r/base/AsIs.html" class="external-link">I</a></span><span class="op">(</span><span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="st">"x y"</span>, <span class="st">"1 2"</span>, <span class="st">"3 4"</span><span class="op">)</span><span class="op">)</span>, delim <span class="op">=</span> <span class="st">" "</span><span class="op">)</span></span></span> |
| <span class="r-out co"><span class="r-pr">#></span> <span style="color: #949494;"># A tibble: 2 x 2</span></span> |
| <span class="r-out co"><span class="r-pr">#></span> x y</span> |
| <span class="r-out co"><span class="r-pr">#></span> <span style="color: #949494; font-style: italic;"><int></span> <span style="color: #949494; font-style: italic;"><int></span></span> |
| <span class="r-out co"><span class="r-pr">#></span> <span style="color: #BCBCBC;">1</span> 1 2</span> |
| <span class="r-out co"><span class="r-pr">#></span> <span style="color: #BCBCBC;">2</span> 3 4</span> |
| </code></pre></div> |
| </div> |
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