Google Git
Sign in
apache / spark-website / 2c562896505588421cce257d111c8ba3805528c2 / . / site / docs / 3.4.3 / api / python / reference / pyspark.pandas / api / pyspark.pandas.groupby.GroupBy.bfill.html
blob: 314532c478a67104b90c26d80ad1071a3fc161f7 [file] [log] [blame]
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>pyspark.pandas.groupby.GroupBy.bfill &#8212; PySpark 3.4.3 documentation</title>
<link rel="stylesheet" href="../../../_static/css/index.73d71520a4ca3b99cfee5594769eaaae.css">
<link rel="stylesheet"
href="../../../_static/vendor/fontawesome/5.13.0/css/all.min.css">
<link rel="preload" as="font" type="font/woff2" crossorigin
href="../../../_static/vendor/fontawesome/5.13.0/webfonts/fa-solid-900.woff2">
<link rel="preload" as="font" type="font/woff2" crossorigin
href="../../../_static/vendor/fontawesome/5.13.0/webfonts/fa-brands-400.woff2">
<link rel="stylesheet"
href="../../../_static/vendor/open-sans_all/1.44.1/index.css">
<link rel="stylesheet"
href="../../../_static/vendor/lato_latin-ext/1.44.1/index.css">
<link rel="stylesheet" href="../../../_static/basic.css" type="text/css" />
<link rel="stylesheet" href="../../../_static/pygments.css" type="text/css" />
<link rel="stylesheet" type="text/css" href="../../../_static/copybutton.css" />
<link rel="stylesheet" type="text/css" href="../../../_static/css/pyspark.css" />
<link rel="preload" as="script" href="../../../_static/js/index.3da636dd464baa7582d2.js">
<script id="documentation_options" data-url_root="../../../" src="../../../_static/documentation_options.js"></script>
<script src="../../../_static/jquery.js"></script>
<script src="../../../_static/underscore.js"></script>
<script src="../../../_static/doctools.js"></script>
<script src="../../../_static/language_data.js"></script>
<script src="../../../_static/clipboard.min.js"></script>
<script src="../../../_static/copybutton.js"></script>
<script crossorigin="anonymous" integrity="sha256-Ae2Vz/4ePdIu6ZyI/5ZGsYnb+m0JlOmKPjt6XZ9JJkA=" src="https://cdnjs.cloudflare.com/ajax/libs/require.js/2.3.4/require.min.js"></script>
<script async="async" src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.5/latest.js?config=TeX-AMS-MML_HTMLorMML"></script>
<script type="text/x-mathjax-config">MathJax.Hub.Config({"tex2jax": {"inlineMath": [["$", "$"], ["\\(", "\\)"]], "processEscapes": true, "ignoreClass": "document", "processClass": "math|output_area"}})</script>
<link rel="canonical" href="https://spark.apache.org/docs/latest/api/python/reference/pyspark.pandas/api/pyspark.pandas.groupby.GroupBy.bfill.html" />
<link rel="search" title="Search" href="../../../search.html" />
<link rel="next" title="pyspark.pandas.groupby.GroupBy.ffill" href="pyspark.pandas.groupby.GroupBy.ffill.html" />
<link rel="prev" title="pyspark.pandas.groupby.GroupBy.fillna" href="pyspark.pandas.groupby.GroupBy.fillna.html" />
<meta name="viewport" content="width=device-width, initial-scale=1" />
<meta name="docsearch:language" content="en" />
</head>
<body data-spy="scroll" data-target="#bd-toc-nav" data-offset="80">
<nav class="navbar navbar-light navbar-expand-lg bg-light fixed-top bd-navbar" id="navbar-main">
<div class="container-xl">
<a class="navbar-brand" href="../../../index.html">
<img src="../../../_static/spark-logo-reverse.png" class="logo" alt="logo" />
</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbar-menu" aria-controls="navbar-menu" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div id="navbar-menu" class="col-lg-9 collapse navbar-collapse">
<ul id="navbar-main-elements" class="navbar-nav mr-auto">
<li class="nav-item ">
<a class="nav-link" href="../../../index.html">Overview</a>
</li>
<li class="nav-item ">
<a class="nav-link" href="../../../getting_started/index.html">Getting Started</a>
</li>
<li class="nav-item ">
<a class="nav-link" href="../../../user_guide/index.html">User Guides</a>
</li>
<li class="nav-item active">
<a class="nav-link" href="../../index.html">API Reference</a>
</li>
<li class="nav-item ">
<a class="nav-link" href="../../../development/index.html">Development</a>
</li>
<li class="nav-item ">
<a class="nav-link" href="../../../migration_guide/index.html">Migration Guides</a>
</li>
</ul>
<ul class="navbar-nav">
</ul>
</div>
</div>
</nav>
<div class="container-xl">
<div class="row">
<div class="col-12 col-md-3 bd-sidebar"><form class="bd-search d-flex align-items-center" action="../../../search.html" method="get">
<i class="icon fas fa-search"></i>
<input type="search" class="form-control" name="q" id="search-input" placeholder="Search the docs ..." aria-label="Search the docs ..." autocomplete="off" >
</form>
<nav class="bd-links" id="bd-docs-nav" aria-label="Main navigation">
<div class="bd-toc-item active">
<ul class="nav bd-sidenav">
<li class="">
<a href="../../pyspark.sql/index.html">Spark SQL</a>
</li>
<li class="active">
<a href="../index.html">Pandas API on Spark</a>
<ul>
<li class="">
<a href="../io.html">Input/Output</a>
</li>
<li class="">
<a href="../general_functions.html">General functions</a>
</li>
<li class="">
<a href="../series.html">Series</a>
</li>
<li class="">
<a href="../frame.html">DataFrame</a>
</li>
<li class="">
<a href="../indexing.html">Index objects</a>
</li>
<li class="">
<a href="../window.html">Window</a>
</li>
<li class="active">
<a href="../groupby.html">GroupBy</a>
</li>
<li class="">
<a href="../resampling.html">Resampling</a>
</li>
<li class="">
<a href="../ml.html">Machine Learning utilities</a>
</li>
<li class="">
<a href="../extensions.html">Extensions</a>
</li>
</ul>
</li>
<li class="">
<a href="../../pyspark.ss/index.html">Structured Streaming</a>
</li>
<li class="">
<a href="../../pyspark.ml.html">MLlib (DataFrame-based)</a>
</li>
<li class="">
<a href="../../pyspark.streaming.html">Spark Streaming (Legacy)</a>
</li>
<li class="">
<a href="../../pyspark.mllib.html">MLlib (RDD-based)</a>
</li>
<li class="">
<a href="../../pyspark.html">Spark Core</a>
</li>
<li class="">
<a href="../../pyspark.resource.html">Resource Management</a>
</li>
<li class="">
<a href="../../pyspark.errors.html">Errors</a>
</li>
</ul>
</nav>
</div>
<div class="d-none d-xl-block col-xl-2 bd-toc">
<nav id="bd-toc-nav">
<ul class="nav section-nav flex-column">
</ul>
</nav>
</div>
<main class="col-12 col-md-9 col-xl-7 py-md-5 pl-md-5 pr-md-4 bd-content" role="main">
<div>
<div class="section" id="pyspark-pandas-groupby-groupby-bfill">
<h1>pyspark.pandas.groupby.GroupBy.bfill<a class="headerlink" href="#pyspark-pandas-groupby-groupby-bfill" title="Permalink to this headline"></a></h1>
<dl class="py method">
<dt id="pyspark.pandas.groupby.GroupBy.bfill">
<code class="sig-prename descclassname">GroupBy.</code><code class="sig-name descname">bfill</code><span class="sig-paren">(</span><em class="sig-param"><span class="n">limit</span><span class="p">:</span> <span class="n">Optional<span class="p">[</span>int<span class="p">]</span></span> <span class="o">=</span> <span class="default_value">None</span></em><span class="sig-paren">)</span> &#x2192; FrameLike<a class="reference internal" href="../../../_modules/pyspark/pandas/groupby.html#GroupBy.bfill"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#pyspark.pandas.groupby.GroupBy.bfill" title="Permalink to this definition"></a></dt>
<dd><p>Synonym for <cite>DataFrame.fillna()</cite> with <code class="docutils literal notranslate"><span class="pre">method=`bfill`</span></code>.</p>
<dl class="field-list">
<dt class="field-odd">Parameters</dt>
<dd class="field-odd"><dl>
<dt><strong>axis</strong><span class="classifier">{0 or <cite>index</cite>}</span></dt><dd><p>1 and <cite>columns</cite> are not supported.</p>
</dd>
<dt><strong>inplace</strong><span class="classifier">boolean, default False</span></dt><dd><p>Fill in place (do not create a new object)</p>
</dd>
<dt><strong>limit</strong><span class="classifier">int, default None</span></dt><dd><p>If method is specified, this is the maximum number of consecutive NaN values to
forward/backward fill. In other words, if there is a gap with more than this number of
consecutive NaNs, it will only be partially filled. If method is not specified,
this is the maximum number of entries along the entire axis where NaNs will be filled.
Must be greater than 0 if not None</p>
</dd>
</dl>
</dd>
<dt class="field-even">Returns</dt>
<dd class="field-even"><dl class="simple">
<dt>DataFrame</dt><dd><p>DataFrame with NA entries filled.</p>
</dd>
</dl>
</dd>
</dl>
<p class="rubric">Examples</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">df</span> <span class="o">=</span> <span class="n">ps</span><span class="o">.</span><span class="n">DataFrame</span><span class="p">({</span>
<span class="gp">... </span> <span class="s1">&#39;A&#39;</span><span class="p">:</span> <span class="p">[</span><span class="mi">1</span><span class="p">,</span> <span class="mi">1</span><span class="p">,</span> <span class="mi">2</span><span class="p">,</span> <span class="mi">2</span><span class="p">],</span>
<span class="gp">... </span> <span class="s1">&#39;B&#39;</span><span class="p">:</span> <span class="p">[</span><span class="mi">2</span><span class="p">,</span> <span class="mi">4</span><span class="p">,</span> <span class="kc">None</span><span class="p">,</span> <span class="mi">3</span><span class="p">],</span>
<span class="gp">... </span> <span class="s1">&#39;C&#39;</span><span class="p">:</span> <span class="p">[</span><span class="kc">None</span><span class="p">,</span> <span class="kc">None</span><span class="p">,</span> <span class="kc">None</span><span class="p">,</span> <span class="mi">1</span><span class="p">],</span>
<span class="gp">... </span> <span class="s1">&#39;D&#39;</span><span class="p">:</span> <span class="p">[</span><span class="mi">0</span><span class="p">,</span> <span class="mi">1</span><span class="p">,</span> <span class="mi">5</span><span class="p">,</span> <span class="mi">4</span><span class="p">]</span>
<span class="gp">... </span> <span class="p">},</span>
<span class="gp">... </span> <span class="n">columns</span><span class="o">=</span><span class="p">[</span><span class="s1">&#39;A&#39;</span><span class="p">,</span> <span class="s1">&#39;B&#39;</span><span class="p">,</span> <span class="s1">&#39;C&#39;</span><span class="p">,</span> <span class="s1">&#39;D&#39;</span><span class="p">])</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">df</span>
<span class="go"> A B C D</span>
<span class="go">0 1 2.0 NaN 0</span>
<span class="go">1 1 4.0 NaN 1</span>
<span class="go">2 2 NaN NaN 5</span>
<span class="go">3 2 3.0 1.0 4</span>
</pre></div>
</div>
<p>Propagate non-null values backward.</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">df</span><span class="o">.</span><span class="n">groupby</span><span class="p">([</span><span class="s1">&#39;A&#39;</span><span class="p">])</span><span class="o">.</span><span class="n">bfill</span><span class="p">()</span><span class="o">.</span><span class="n">sort_index</span><span class="p">()</span>
<span class="go"> B C D</span>
<span class="go">0 2.0 NaN 0</span>
<span class="go">1 4.0 NaN 1</span>
<span class="go">2 3.0 1.0 5</span>
<span class="go">3 3.0 1.0 4</span>
</pre></div>
</div>
</dd></dl>
</div>
</div>
<div class='prev-next-bottom'>
<a class='left-prev' id="prev-link" href="pyspark.pandas.groupby.GroupBy.fillna.html" title="previous page">pyspark.pandas.groupby.GroupBy.fillna</a>
<a class='right-next' id="next-link" href="pyspark.pandas.groupby.GroupBy.ffill.html" title="next page">pyspark.pandas.groupby.GroupBy.ffill</a>
</div>
</main>
</div>
</div>
<script src="../../../_static/js/index.3da636dd464baa7582d2.js"></script>
<footer class="footer mt-5 mt-md-0">
<div class="container">
<p>
&copy; Copyright .<br/>
Created using <a href="http://sphinx-doc.org/">Sphinx</a> 3.0.4.<br/>
</p>
</div>
</footer>
</body>
</html>