Pandas series index. Generate a new DataFrame or Series with the index reset.

Pandas series index. min # Series. 55 times pandas. In this section, we will focus on the final The index can be thought of as an immutable ordered set (technically a multi-set, as it may contain duplicate labels), and is used to index and align data in pandas. The index can be thought of as an immutable ordered set (technically a multi-set, as it may contain duplicate labels), and is used to index and align data in pandas. shift(periods=1, freq=None, axis=0, fill_value=<no_default>, suffix=None) [source] # Shift index by desired number of periods with an optional time freq. The index is used for label-based access and alignment, and can be accessed or modified using this attribute. Operations between Series (+, -, /, *, **) align values based on their associated index values– they need not be the same length. Series(data[' Nov 23, 2024 · Learn how to access the first element of a Pandas Series without relying on the index. copybool, default False Copy input data. 概要 Series の値を取得、設定する方法について解説します。関連記事 pandas - DataFrame のインデックス操作まとめ - pystyle Series のインデックスを取得する pandas. iat Access a single value by integer position. See the user guide for more usages. concat # pandas. This article explores multiple ways to create a Pandas Series with step-by-step explanations and examples Feb 19, 2024 · The input is a Pandas Series and a value to find; the desired output is the index (or indices) at which the value occurs in the Series. Jul 26, 2025 · In this article, we’ll see various ways to index and select data in Pandas which shows us how to access the parts of our dataset. likestr Keep labels from axis for Feb 18, 2025 · At first glance, sorting a pandas Series seems straightforward. Labels need not be unique but must be a hashable type. new_series = pd. This can be used to group large amounts of data and compute Indexing and selecting data # The axis labeling information in pandas objects serves many purposes: Identifies data (i. iteritems())) print (s1) a A b B c C d D e E f F g G h H i I j J dtype: object Another the fastest: print (pd. But once NaN values, indexing issues, and in-place modifications come into play, things can get tricky. Jul 11, 2025 · Pandas Series is a one-dimensional labeled array capable of holding data of any type (integer, string, float, python objects, etc. The index is an immutable ordered set that can be aligned and indexed in pandas. When drop is True, a Series is returned. The newly created columns will come first in the DataFrame, followed by the original Series values. items # Series. Parameters: axis{0 or ‘index’} Unused Parameters: dataarray-like (1-dimensional) dtypestr, numpy. Get practical examples, speed tests, and alternative solutions. loc [source] # Access a group of rows and columns by label (s) or a boolean array. Series (data = [1,2,3], index = ['A', 'B', 'C']) How can I change the order of the index, so that s becomes B 2 A 1 C 3 I tried s ['B','A Return Addition of series and other, element-wise (binary operator add). get_indexer # final Index. For NumPy native types, this is a thin (no copy) wrapper around numpy. provides metadata) using known indicators, important for analysis, visualization, and interactive console display. Previously only int64/uint64/float64 dtypes were accepted. If cond is callable, it is computed on the Series/DataFrame and should return Feb 12, 2018 · pandas. Parameters: itemslist-like Keep labels from axis which are in items. From basic reordering to advanced techniques for dealing with missing data, understanding how to utilize this function effectively can enhance your data analysis and manipulation capabilities pandas. . Allowed inputs are: A single label, e. Feb 19, 2024 · Problem Formulation: While working with Pandas, a versatile data manipulation library in Python, changing the index of a Series can be a common task. Series. The index can replace the existing index or expand on it. Pandas provide various Series methods and attributes to retrieve the data from Series. str. Lets say I have a MultiIndex Series s: >>> s values a b 1 2 0. count('H')==1)] I admit it is Mar 10, 2023 · This is a concise and comprehensive cheat sheet that focuses on Series in Pandas. See code examples, explanations, and tips for handling errors and multiple occurrences. The result index will be the sorted union of the two indexes. iteritems())) The slowest run took 6. Can also add a layer of hierarchical indexing on the concatenation axis, which may be useful if the labels are the same The index of a Series is used to label and identify each element of the underlying data. Where False, replace with corresponding value from other. com Apr 12, 2024 · Learn how to use bracket notation, index attribute, where method, argmax method, list method, try/except block, and Index class to find an element's index in a Pandas Series. array differs from . Learn about Python Pandas Series, a powerful data structure for handling one-dimensional data with ease. A new object is produced unless the new index is equivalent to the current one and copy=False. concat(objs, *, axis=0, join='outer', ignore_index=False, keys=None, levels=None, names=None, verify_integrity=False, sort=False, copy=None) [source] # Concatenate pandas objects along a particular axis. This comprehensive guide explores the Pandas Series index in depth, covering its creation, manipulation, properties, and practical applications. 3 4 4 0. How can I get the index of certain element of a Series in python pandas? (first occurrence would suffice) I. Example: import A Pandas Series is a one-dimensional labeled array that can hold data of any type. When freq is not passed, shift the index without realigning the data. If you want the index of the minimum, use idxmin. DataFrame. get_indexer(target, method=None, limit=None, tolerance=None) [source] # Compute indexer and mask for new index given the current index. Method 1: Using Series. The index of a DataFrame is a series of labels that identify each row. Whether you’re aligning data or just reordering it for aesthetic purposes, understanding how to modify Mar 31, 2022 · This tutorial explains how to get a value from a pandas Series, including several examples. See the Indexing and Selecting Data for general indexing documentation. sort_index # Series. reindex # Series. Nov 18, 2021 · A pandas Series holds labeled data, by using these labels we can access series elements and we can do manipulations on our data. values # property Series. If freq is passed (in this case, the index must be date or datetime, or it will raise a NotImplementedError), the index will be increased using Oct 20, 2016 · One posible solution is swap keys and values by: s1 = pd. Parameters: targetIndex Aug 5, 2013 · Pandas allows you to create a DataFrame from a dict with Series as the values and the column names as the keys. You can already get the future behavior and improvements through enabling copy on write pd. Whether elements in Series are contained in values. , position-based index). array # property Series. What's reputation and how do I get it? Instead, you can save this post to reference later. DataFrame, pandas. mode pandas. items() [source] # Lazily iterate over (index, value) tuples. take to align the current data to the new index. Copy-on-Write will be enabled by default, which means that all methods with a copy keyword will use a lazy copy mechanism to defer the copy and ignore the copy keyword. In this article, we will discuss different ways to create index in a pandas series. The labels can be integers, strings, or any other hashable type. series_of_tuples[series_of_tuples. Practical examples included. sort_index(*, axis=0, level=None, ascending=True, inplace=False, kind='quicksort', na_position='last', sort_remaining=True, ignore_index=False, key=None) [source] # Sort Series by index labels. Returns: pandas Changed in version 2. Series, which is a 1-D labeled array capable of holding any data. Enables automatic and explicit data alignment. 1. Jul 11, 2025 · Pandas Series is a one-dimensional labeled array capable of holding any data type (integers, strings, floats, etc. Remove elements of a Series based on specifying the index labels. Series(s. Parameters: axis{index (0)} Axis for the function to be applied on. If no index is specified Pandas automatically assigns default integer indices starting from 0. Jun 19, 2023 · In this blog, we will delve into the process of identifying the index of an element within a Pandas Series, a task often undertaken by data scientists and software engineers. I'm using python 2. Feb 10, 2019 · Pandas series is a One-dimensional ndarray with axis labels. A pandas Series holds labeled data and these labels are called indexes, by using these labels we can access series elements and we can do manipulations on our data. iat Access a single value for a row/column pair by integer position. Jul 11, 2025 · Pandas Series from Dictionary In this article, you will learn about the different methods of configuring the pandas. tupleize_colsbool (default: True) When True, attempt to create a MultiIndex if possible. Series () command to make a pandas series from a dictionary followed by a few practical tips for using them. index用法及代码示例 Python是进行数据分析的一种出色语言，主要是因为以数据为中心的python软件包具有奇妙的生态系统。 Feb 17, 2024 · In summary, this guide covered several methods for getting a list of indexes in a Pandas Series, from simple attribute access to more advanced techniques involving Boolean indexing and Pandas data accessors. Examples To create a Series with a custom index and view the index labels: Operations between Series (+, -, /, *, **) align values based on their associated index values– they need not be the same length. apply(lambda x: x. Indexing Data using the [] Operator The [] operator is the basic and frequently used method for indexing in Pandas. Elements of a series can be accessed in two ways: Accessing Element from Series with Position Accessing Element Using Label (index) In pandas. reindex() method in pandas is a powerful tool for data manipulation, offering versatility in handling data index changes. However, in some situations, we need to get all labels and values separately. Seriesの []によるインデックス指定で、行・列および要素を選択し抽出・取得できる。 []に指定する値のタイプによって取得できるデータが異なる。 Index objects # Index # Many of these methods or variants thereof are available on the objects that contain an index (Series/DataFrame) and those should most likely be used before calling these methods directly. I have a Date Time series from which I am trying to select certain elements, along with their date time index in order to a pandas. This is convenient if you want to create a lazy iterator. Returns: ExtensionArray An ExtensionArray of the values stored within. Dec 5, 2022 · Pandas series objects are used to store data when we need to access it using its position as well as labels. Method 2: Using the . When it finds a Series as a value, it uses the Series index as part of the DataFrame index. Each of the returned indexes corresponds to the position where the substring is fully contained between [start:end]. at Access a single value by label. Examples To create a Series with a custom index and view the index labels: pandas. What is a Series? A Pandas Series is like a column in a table. Return a boolean Series showing whether each element in the Series matches an element in the passed sequence of values exactly. iloc[] property is used to access a Series by its integer location (i. It will help you quickly look up attributes, methods, syntaxes, and popular operations when solving problems related to series. The indexer should be then used as an input to ndarray. Note that this routine does not filter a dataframe on its contents. reset_index() function generate a new DataFrame or Series with the index reset. set_index() A series in Python pandas is a kind of one dimensional array of any datatype. For extension types, this is the actual array. name # property Series. Selecting a row of pandas series/dataframe by integer index Asked 12 years, 3 months ago Modified 4 months ago Viewed 1. This is the equivalent of the numpy. Places NA/NaN in locations having no value in the previous index. See full list on sparkbyexamples. The primary focus will be on Series and DataFrame as they have received more development attention in this area. Parameters: keyslabel or array-like or list of pandas. dtype, or ExtensionDtype, optional Data type for the output Index. In this article, I will explain how to rearrange the index values of a given series in a specific order. iloc[] Property The . Dec 5, 2024 · Explore various efficient methods to find the index of an element in a Pandas Series. Using Series () method without index parameter In this case, dictionary keys are taken in a sorted order to construct the Dec 2, 2022 · We use pandas series objects for various data processing tasks in python. 7 and I want to apply a function which uses the index of the row: def f(x pandas. Set the DataFrame index (row labels) using one or more existing columns or arrays (of the correct length). Mar 27, 2024 · In Series every element contains the corresponding index/index labels, by using these indexes we can get the values from Pandas Series. index By default, the original index and original name is reused. dtypes for data Feb 17, 2024 · Method #1 – Using iteritems () The iteritems() function yields pairs of index and value. Parameters PythonのPandasにおけるSeriesの使い方を初心者向けに解説した記事です。Seriesの作成方法や、要素の抽出、追加、削除、インデックスの利用方法など、Seriesについてはこれだけを読んでおけば良いよう、徹底的に解説しています。 pandas. Notes For more information on pandas index ing, see the indexing user guide. May 29, 2020 · You'll need to complete a few actions and gain 15 reputation points before being able to upvote. Series(dict((v,k) for k,v in s. Returns: Index pandas. Parameters: labelssingle label or list-like Index pandas. drop # Series. Designed for both beginners and experienced users, this blog provides detailed explanations and examples to ensure you can leverage the Series index effectively in your data analysis workflows. Index. Python Pandas Series. The name of a Series becomes its index or column name if it is used to form a DataFrame. loc # property Series. In either case, if inplace=True, no value is returned. It is also used whenever displaying the Series using the interpreter. Returns: label (hashable object) The name of the Series, also the column name if part of a DataFrame. index(sub, start=0, end=None) [source] # Return lowest indexes in each string in Series/Index. In this tutorial, you will learn about Pandas Series with the help of examples. MultiIndex / advanced indexing # This section covers indexing with a MultiIndex and other advanced indexing features. , I'd Jun 24, 2025 · In pandas, Series. loc[] is primarily label based, but may also be used with a boolean array. Allows optional set logic along the other axes. This method is particularly useful Accessors # pandas provides dtype-specific methods under various accessors. An element in the series can be accessed similarly to that in an ndarray. ), with each element having an associated label known as its index. If you want to get labels and values individually. For instance, you may have a Series with indices ranging from 0 to n and wish to adjust these to a new set of labels for better data comprehension or to conform with other datasets. Method 1: Using the index attribute and list comprehension This method involves accessing the index attribute of the Series and using list comprehension to create a list of indices that match the given value. Upvoting indicates when questions and answers are useful. Import Pandas and create a Series. It allows us to select columns and filter rows based on conditions. Use a for loop in combination with iteritems() to iterate through the Series. shift # Series. ndarray. 5 or 'a', (note that 5 is interpreted as a label of the index, and never as an integer position along the index). Each value in a Series is associated with an index, which makes data retrieval and manipulation easy. array [source] # The ExtensionArray of the data backing this Series or Index. where(cond, other=nan, *, inplace=False, axis=None, level=None) [source] # Replace values where the condition is False. Pandas如何更改Pandas Series的索引值在本文中，我们将介绍如何更改Pandas Series的索引值。 Pandas是一个非常流行的Python数据分析库，Series是其中一种重要的数据结构。每个Series都包含一个索引和一组值，我们可以使用索引来访问这些值。 pandas. If cond is callable, it is computed on the Series/DataFrame and should return Notes For more information on pandas indexing, see the indexing user guide. where # Series. You can bookmark this page Generate a new DataFrame or Series with the index reset. Pandas Series. We will explore practical ways to set or change the index in a pandas Series, starting from a Series with a default integer index, with the aim of setting a new index. For Feb 2, 2015 · In my case I had a pandas Series where the values are tuples of characters: Out[67] 0 (H, H, H, H) 1 (H, H, H, T) 2 (H, H, T, H) 3 (H, H, T, T) 4 (H, T, H, H) Therefore I could use indexing to filter the series, but to create the index I needed apply. Feb 17, 2024 · Overview Updating the index of a Pandas Series is a common task which significantly impacts data manipulation and presentation. When using a multi-index, labels on different levels can be removed by specifying the level. values, which may require converting the data to a different form. Pandas 在Pandas Series中查找元素的索引在本文中，我们将介绍如何使用Pandas查找元素在Series中的索引。 Pandas是Python数据分析的重要工具，提供强大的数据结构和数据分析方法。 Series是Pandas中的一种基本数据结构，类似于一维数组。阅读更多：Pandas 教程 1. Syntax: pandas. Aug 20, 2013 · This solution only works if your series has a sequential integer index. Using Series() Without an Index Argument The simplest way to create a Pandas Series is by passing a list to the Series() method. 0. Jul 11, 2025 · In this article we will understand how to create a Pandas series from lists along with explanations and examples. index # Series. Series([421, 122, 275, 847, 175]) index_v You can also index find any number occurrence of the value by treating the the above statement as a list: animals[animas == 'mammoth']. The copy keyword will be removed in a future version of pandas. iloc Access a group of rows and columns by integer position (s). index # DataFrame. This comes handy when index is need to be MultiIndex is also called Hierarchical Indexing, it is a powerful feature in pandas that allows you to work with higher-dimensional data in lower-dimensional structures like Series (1D) and DataFrame (2D). A groupby operation involves some combination of splitting the object, applying a function, and combining the results. Parameters: condbool Series/DataFrame, array-like, or callable Where cond is True, keep the original value. index values. In this section, we will focus on the final point: namely, how to slice, dice, and generally get and set subsets of pandas objects. values [source] # Return Series as ndarray or ndarray-like depending on the dtype. Explore its features, methods, and practical applications. Feb 24, 2024 · In this tutorial, we will focus on creating Multi-Index Series in Pandas, providing you with five practical examples to enhance your data manipulation skills. Feb 19, 2024 · This code snippet creates a pandas Series with labeled index and fetches the value at index ‘c’, which is 30. Series. If not specified, this will be inferred from data. It shows how to use the [] operator with a labeled index to retrieve the requested value from the Series. set_index(keys, *, drop=True, append=False, inplace=False, verify_integrity=False) [source] # Set the DataFrame index using existing columns. May 13, 2015 · I have a pandas series: import pandas as pd s = pd. x = pd. name [source] # Return the name of the Series. This is useful when the index needs to be treated as a column, or when the index is meaningless and needs to be reset to the default before another operation. The labels need not be unique but must be a hashable type. reindex () Method of pandas module for performing this task. Aug 20, 2013 · I know this is a very basic question but for some reason I can't find an answer. groupby # Series. pandas. The filter is applied to the labels of the index. Returns a new Series sorted by label if inplace argument is False, otherwise updates the original series and returns None. reindex(index=None, *, axis=None, method=None, copy=None, level=None, fill_value=None, limit=None, tolerance=None) [source] # Conform Series to new index with optional filling logic. Note The copy keyword will change behavior in pandas 3. options. drop(labels=None, *, axis=0, index=None, columns=None, level=None, inplace=False, errors='raise') [source] # Return Series with specified index labels removed. Jan 4, 2020 · How can I change the index values of a Pandas Series from the regular integer value that they default to, to values within a list that I have? e. 4m times How do I get the index column name in Python's pandas? Here's an example dataframe: Column 1 Index Title Apples 1 Oranges 2 Puppies 3 Duc pandas. Returns: iterable Iterable of tuples containing the (index, value) pairs from a Series. If your series index is by datetime, this doesn't work. Feb 19, 2024 · Changing the index can be essential for data alignment operations, merging data sets, and improving data retrieval speeds. 1 3 6 0. It’s a straightforward way to iterate over both, which can be particularly useful when the series has a meaningful index. In this article, we will discuss how to rename the index in a pandas series. This method allows you to specify the new order of the index labels. Returns: Series or DataFrame or None When drop is False (the default), a DataFrame is returned. Each value in series associated with the index starts 0 to n-1. groupby(by=None, axis=0, level=None, as_index=True, sort=True, group_keys=True, observed=<no_default>, dropna=True) [source] # Group Series using a mapper or by a Series of columns. 0: Index can hold all numpy numeric dtypes (except float16). e. This method returns an iterable tuple (index, value). These are separate namespaces within Series that only apply to specific data types. DataFrame. Allows intuitive getting and setting of subsets of the data set. See also DataFrame. set_index # DataFrame. It is a one-dimensional array holding data of any type. . Learn how to create and modify the index of a pandas Series, which is used to label and identify each element of the data. Feb 18, 2024 · In conclusion, the Series. Jul 11, 2025 · A Pandas Series is like a single column of data in a spreadsheet. The object supports both integer- and label-based indexing and provides a host of methods for performing operations involving the index. Jun 10, 2025 · To change the index order in a Pandas Series, you can use the reindex() method. Pandas, a widely-used data manipulation library in Python, offers robust data structures and functions designed for efficient handling of tabular and timeseries data. filter(items=None, like=None, regex=None, axis=None) [source] # Subset the dataframe rows or columns according to the specified index labels. My condition is "find all tuples which have exactly one 'H'". ndarray method argmin. min(axis=0, skipna=True, numeric_only=False, **kwargs) [source] # Return the minimum of the values over the requested axis. Parameters PythonのPandasにおけるSeriesの使い方を初心者向けに解説した記事です。Seriesの作成方法や、要素の抽出、追加、削除、インデックスの利用方法など、Seriesについてはこれだけを読んでおけば良いよう、徹底的に解説しています。 Jan 17, 2014 · I'm having a bit of a slow moment with selection and indexing in pandas. Let’s say you have a Series with default integer indices and pandas. For Series this parameter is unused and defaults to 0. 7 to take a numerical column of my dataframe data and make it an individual object (series) with an index of dates that is another column from data. at Access a single value for a row/column pair by label. Series (data, index, dtype, copy) Parameters: data takes ndarrys, list, constants. Then we can use the index and values attributes of the Series Accessors # pandas provides dtype-specific methods under various accessors. g. filter # Series. Labels can be called indexes and data present in a series called values. loc Access a group of rows and columns by label (s). Parameters The index can be thought of as an immutable ordered set (technically a multi-set, as it may contain duplicate labels), and is used to index and align data in pandas. With MultiIndex, pandas objects have multiple levels of index labels. index # The index (row labels) of the DataFrame. index. values, index=s )) a A b B c C d D e E f F g G h H i I j J dtype: object Timings: In [63]: %timeit pd. One easy way to re-arrange the index would be to reassign the same Series with the order of the indexes changed. It is a one-dimensional array that can hold many types of data such as numbers, words or even other Python objects. ). index attribute is used to retrieve the index labels associated with the given Series object. Series Jul 15, 2025 · Suppose we want to change the order of the index of series, then we have to use the Series. index[1] #retrieves index of second occurrence of value. nameobject Name to be stored in the index. Equivalent to series + other, but with support to substitute a fill_value for missing data in either one of the inputs. By the end of this tutorial, creating and manipulating multi-index Series will be second nature to you. ggmy eevki zvkimf rjehmp yumj amxygq ymg zmisntp skenuir qyhnj