DataFrame.drop(labels=None, *, axis=0, index=None, columns=None, level=None, inplace=False, errors='raise') [source] #. Drop specified labels from rows or columns. Remove rows or columns by specifying label names and corresponding axis, or by directly specifying index or column names. When using a multi-index, labels on different levels can be ...DataFrame.set_index(keys, *, drop=True, append=False, inplace=False, verify_integrity=False) [source] #. Set the DataFrame index using existing columns. Set the DataFrame index (row labels) using one or more existing columns or arrays (of the correct length). The index can replace the existing index or expand on it. This parameter can be either ... When your DataFrame contains a mixture of data types, DataFrame.values may involve copying data and coercing values to a common dtype, a relatively expensive operation. DataFrame.to_numpy(), being a method, makes it clearer that the returned NumPy array may not be a view on the same data in the DataFrame. Accelerated operations# Aug 22, 2023 · Pandas DataFrame describe () Pandas describe () is used to view some basic statistical details like percentile, mean, std, etc. of a data frame or a series of numeric values. When this method is applied to a series of strings, it returns a different output which is shown in the examples below. Let’ see how we can split the dataframe by the Name column: grouped = df.groupby (df [ 'Name' ]) print (grouped.get_group ( 'Jenny' )) What we have done here is: Created a group by object called grouped, splitting the dataframe by the Name column, Used the .get_group () method to get the dataframe’s rows that contain ‘Jenny’.DataFrame.sort_values(by, *, axis=0, ascending=True, inplace=False, kind='quicksort', na_position='last', ignore_index=False, key=None) [source] #. Sort by the values along either axis. Name or list of names to sort by. if axis is 0 or ‘index’ then by may contain index levels and/or column labels. if axis is 1 or ‘columns’ then by may ...The StructType and StructFields are used to define a schema or its part for the Dataframe. This defines the name, datatype, and nullable flag for each column. StructType object is the collection of StructFields objects. It is a Built-in datatype that contains the list of StructField.Python | Pandas DataFrame.columns. Pandas DataFrame is a two-dimensional size-mutable, potentially heterogeneous tabular data structure with labeled axes (rows and columns). Arithmetic operations align on both row and column labels. It can be thought of as a dict-like container for Series objects. This is the primary data structure of the Pandas.dataframe[-1] will treat your data in vector form, thus returning all but the very first element [[edit]] which as has been pointed out, turns out to be a column, as a data.frame is a list. dataframe[,-1] will treat your data in matrix form, returning all but the first column.The primary pandas data structure. Parameters: data : numpy ndarray (structured or homogeneous), dict, or DataFrame. Dict can contain Series, arrays, constants, or list-like objects. Changed in version 0.23.0: If data is a dict, argument order is maintained for Python 3.6 and later. index : Index or array-like. Pandas 数据结构 - DataFrame. DataFrame 是一个表格型的数据结构，它含有一组有序的列，每列可以是不同的值类型（数值、字符串、布尔型值）。DataFrame 既有行索引也有列索引，它可以被看做由 Series 组成的字典（共同用一个索引）。 DataFrame 构造方法如下：Divides the values of a DataFrame with the specified value (s), and floor the values. ge () Returns True for values greater than, or equal to the specified value (s), otherwise False. get () Returns the item of the specified key. groupby () Groups the rows/columns into specified groups. Feb 20, 2019 · Python | Pandas DataFrame.columns. Pandas DataFrame is a two-dimensional size-mutable, potentially heterogeneous tabular data structure with labeled axes (rows and columns). Arithmetic operations align on both row and column labels. It can be thought of as a dict-like container for Series objects. This is the primary data structure of the Pandas. DataFrame.corr (col1, col2 [, method]) Calculates the correlation of two columns of a DataFrame as a double value. DataFrame.count () Returns the number of rows in this DataFrame. DataFrame.cov (col1, col2) Calculate the sample covariance for the given columns, specified by their names, as a double value. pandas.DataFrame.rename# DataFrame. rename (mapper = None, *, index = None, columns = None, axis = None, copy = None, inplace = False, level = None, errors = 'ignore') [source] # Rename columns or index labels. Function / dict values must be unique (1-to-1). Labels not contained in a dict / Series will be left as-is. Extra labels listed don’t ...Dec 26, 2022 · The StructType and StructFields are used to define a schema or its part for the Dataframe. This defines the name, datatype, and nullable flag for each column. StructType object is the collection of StructFields objects. It is a Built-in datatype that contains the list of StructField. Convert columns to the best possible dtypes using dtypes supporting pd.NA. DataFrame.infer_objects ( [copy]) Attempt to infer better dtypes for object columns. DataFrame.copy ( [deep]) Make a copy of this object's indices and data. DataFrame.bool () Return the bool of a single element Series or DataFrame. Pandas DataFrame describe () Pandas describe () is used to view some basic statistical details like percentile, mean, std, etc. of a data frame or a series of numeric values. When this method is applied to a series of strings, it returns a different output which is shown in the examples below.By default, convert_dtypes will attempt to convert a Series (or each Series in a DataFrame) to dtypes that support pd.NA. By using the options convert_string, convert_integer, convert_boolean and convert_floating, it is possible to turn off individual conversions to StringDtype, the integer extension types, BooleanDtype or floating extension ... DataFrame.astype(dtype, copy=None, errors='raise') [source] #. Cast a pandas object to a specified dtype dtype. Parameters: dtypestr, data type, Series or Mapping of column name -> data type. Use a str, numpy.dtype, pandas.ExtensionDtype or Python type to cast entire pandas object to the same type. Feb 19, 2021 · Python | Pandas dataframe.add () Python is a great language for doing data analysis, primarily because of the fantastic ecosystem of data-centric Python packages. Pandas is one of those packages and makes importing and analyzing data much easier. Dataframe.add () method is used for addition of dataframe and other, element-wise (binary operator ... The primary pandas data structure. Parameters: data : numpy ndarray (structured or homogeneous), dict, or DataFrame. Dict can contain Series, arrays, constants, or list-like objects. Changed in version 0.23.0: If data is a dict, argument order is maintained for Python 3.6 and later. index : Index or array-like.Returns a new DataFrame containing union of rows in this and another DataFrame. unpersist ([blocking]) Marks the DataFrame as non-persistent, and remove all blocks for it from memory and disk. unpivot (ids, values, variableColumnName, …) Unpivot a DataFrame from wide format to long format, optionally leaving identifier columns set. where ...A Pandas DataFrame is a 2 dimensional data structure, like a 2 dimensional array, or a table with rows and columns. Example Get your own Python Server Create a simple Pandas DataFrame: import pandas as pd data = { "calories": [420, 380, 390], "duration": [50, 40, 45] } #load data into a DataFrame object: df = pd.DataFrame (data) print(df) ResultApply a function to a Dataframe elementwise. Deprecated since version 2.1.0: DataFrame.applymap has been deprecated. Use DataFrame.map instead. This method applies a function that accepts and returns a scalar to every element of a DataFrame. Python function, returns a single value from a single value. If ‘ignore’, propagate NaN values ...A DataFrame is a data structure that organizes data into a 2-dimensional table of rows and columns, much like a spreadsheet. DataFrames are one of the most common data structures used in modern data analytics because they are a flexible and intuitive way of storing and working with data.pandas.DataFrame.isin. #. Whether each element in the DataFrame is contained in values. The result will only be true at a location if all the labels match. If values is a Series, that’s the index. If values is a dict, the keys must be the column names, which must match. If values is a DataFrame, then both the index and column labels must match. DataFrame.shape is an attribute (remember tutorial on reading and writing, do not use parentheses for attributes) of a pandas Series and DataFrame containing the number of rows and columns: (nrows, ncolumns). A pandas Series is 1-dimensional and only the number of rows is returned. I’m interested in the age and sex of the Titanic passengers. DataFrame# DataFrame is a 2-dimensional labeled data structure with columns of potentially different types. You can think of it like a spreadsheet or SQL table, or a dict of Series objects. It is generally the most commonly used pandas object. Like Series, DataFrame accepts many different kinds of input: Dict of 1D ndarrays, lists, dicts, or SeriesA bar plot is a plot that presents categorical data with rectangular bars with lengths proportional to the values that they represent. A bar plot shows comparisons among discrete categories. One axis of the plot shows the specific categories being compared, and the other axis represents a measured value. Parameters. xlabel or position, optional. DataFrame# DataFrame is a 2-dimensional labeled data structure with columns of potentially different types. You can think of it like a spreadsheet or SQL table, or a dict of Series objects. It is generally the most commonly used pandas object. Like Series, DataFrame accepts many different kinds of input: Dict of 1D ndarrays, lists, dicts, or Series property DataFrame.loc [source] #. Access a group of rows and columns by label (s) or a boolean array. .loc [] is primarily label based, but may also be used with a boolean array. Allowed inputs are: A single label, e.g. 5 or 'a', (note that 5 is interpreted as a label of the index, and never as an integer position along the index). pd.DataFrame.query is a very elegant/intuitive way to perform this task, but is often slower. However, if you pay attention to the timings below, for large data, the ...pandas.DataFrame.columns# DataFrame. columns # The column labels of the DataFrame. Examples >>> df = pd.DataFrame Creation¶ A PySpark DataFrame can be created via pyspark.sql.SparkSession.createDataFrame typically by passing a list of lists, tuples, dictionaries and pyspark.sql.Row s, a pandas DataFrame and an RDD consisting of such a list. pyspark.sql.SparkSession.createDataFrame takes the schema argument to specify the schema of the DataFrame ... Create a data frame using the function pd.DataFrame () The data frame contains 3 columns and 5 rows. Print the data frame output with the print () function. We write pd. in front of DataFrame () to let Python know that we want to activate the DataFrame () function from the Pandas library. Be aware of the capital D and F in DataFrame! pandas.DataFrame.dtypes #. pandas.DataFrame.dtypes. #. Return the dtypes in the DataFrame. This returns a Series with the data type of each column. The result’s index is the original DataFrame’s columns. Columns with mixed types are stored with the object dtype. See the User Guide for more.Jul 31, 2015 · In many situations, a custom attribute attached to a pd.DataFrame object is not necessary. In addition, note that pandas-object attributes may not serialize. So pickling will lose this data. Instead, consider creating a dictionary with appropriately named keys and access the dataframe via dfs['some_label']. df = pd.DataFrame() dfs = {'some ... A Data frame is a two-dimensional data structure, i.e., data is aligned in a tabular fashion in rows and columns. Pandas DataFrame consists of three principal components, the data, rows, and columns. We will get a brief insight on all these basic operation which can be performed on Pandas DataFrame :Divides the values of a DataFrame with the specified value (s), and floor the values. ge () Returns True for values greater than, or equal to the specified value (s), otherwise False. get () Returns the item of the specified key. groupby () Groups the rows/columns into specified groups.Feb 19, 2021 · Python | Pandas dataframe.add () Python is a great language for doing data analysis, primarily because of the fantastic ecosystem of data-centric Python packages. Pandas is one of those packages and makes importing and analyzing data much easier. Dataframe.add () method is used for addition of dataframe and other, element-wise (binary operator ... A data frame is a structured representation of data. Let's define a data frame with 3 columns and 5 rows with fictional numbers: Example import pandas as pd d = {'col1': [1, 2, 3, 4, 7], 'col2': [4, 5, 6, 9, 5], 'col3': [7, 8, 12, 1, 11]} df = pd.DataFrame (data=d) print(df) Try it Yourself » Example Explained Import the Pandas library as pdOct 13, 2021 · Dealing with Rows and Columns in Pandas DataFrame. A Data frame is a two-dimensional data structure, i.e., data is aligned in a tabular fashion in rows and columns. We can perform basic operations on rows/columns like selecting, deleting, adding, and renaming. In this article, we are using nba.csv file. axis {0 or ‘index’} for Series, {0 or ‘index’, 1 or ‘columns’} for DataFrame. Axis along which to fill missing values. For Series this parameter is unused and defaults to 0. inplace bool, default False. If True, fill in-place. Note: this will modify any other views on this object (e.g., a no-copy slice for a column in a DataFrame).pandas.DataFrame.dtypes #. pandas.DataFrame.dtypes. #. Return the dtypes in the DataFrame. This returns a Series with the data type of each column. The result’s index is the original DataFrame’s columns. Columns with mixed types are stored with the object dtype. See the User Guide for more.Returns a new DataFrame using the row indices in rowIndices. Filter(PrimitiveDataFrameColumn<Int64>) Returns a new DataFrame using the row indices in rowIndices. FromArrowRecordBatch(RecordBatch) Wraps a DataFrame around an Arrow Apache.Arrow.RecordBatch without copying data. GroupBy(String) pandas.DataFrame.rename# DataFrame. rename (mapper = None, *, index = None, columns = None, axis = None, copy = None, inplace = False, level = None, errors = 'ignore') [source] # Rename columns or index labels. Function / dict values must be unique (1-to-1). Labels not contained in a dict / Series will be left as-is. Extra labels listed don’t ... DataFrame.mask(cond, other=_NoDefault.no_default, *, inplace=False, axis=None, level=None) [source] #. Replace values where the condition is True. Where cond is False, keep the original value. Where True, replace with corresponding value from other . If cond is callable, it is computed on the Series/DataFrame and should return boolean Series ... A Dask DataFrame is a large parallel DataFrame composed of many smaller pandas DataFrames, split along the index. These pandas DataFrames may live on disk for larger-than-memory computing on a single machine, or on many different machines in a cluster. One Dask DataFrame operation triggers many operations on the constituent pandas DataFrames.Mar 7, 2022 · Add a Row to a Pandas DataFrame. The easiest way to add or insert a new row into a Pandas DataFrame is to use the Pandas .concat () function. To learn more about how these functions work, check out my in-depth article here. In this section, you’ll learn three different ways to add a single row to a Pandas DataFrame. Since values are sorted, it is ok to take the first lines for each case. targets = df.groupby (level='case').first () * 0.926 print (targets) 1 2 3 case 1014 18.75150 26.95586 20.38126 1015 18.72372 27.05772 20.19606 1016 20.14050 27.01142 20.20532. Now, How could I simply build the following dataframe, which shows time t at wich each object ...Extracting specific rows of a pandas dataframe. df2[1:3] That would return the row with index 1, and 2. The row with index 3 is not included in the extract because that’s how the slicing syntax works. Note also that row with index 1 is the second row. Row with index 2 is the third row and so on. If you’re wondering, the first row of the ... First, if you have the strings 'TRUE' and 'FALSE', you can convert those to boolean True and False values like this:. df['COL2'] == 'TRUE' That gives you a bool column. You can use astype to convert to int (because bool is an integral type, where True means 1 and False means 0, which is exactly what you want):pandas.DataFrame.at# property DataFrame. at [source] #. Access a single value for a row/column label pair. Similar to loc, in that both provide label-based lookups.Use at if you only need to get or set a single value in a DataFrame or Series.datandarray (structured or homogeneous), Iterable, dict, or DataFrame. Dict can contain Series, arrays, constants, dataclass or list-like objects. If data is a dict, column order follows insertion-order. If a dict contains Series which have an index defined, it is aligned by its index.Marks the DataFrame as non-persistent, and remove all blocks for it from memory and disk. where (condition) where() is an alias for filter(). withColumn (colName, col) Returns a new DataFrame by adding a column or replacing the existing column that has the same name. withColumnRenamed (existing, new) Returns a new DataFrame by renaming an ...Let’ see how we can split the dataframe by the Name column: grouped = df.groupby (df [ 'Name' ]) print (grouped.get_group ( 'Jenny' )) What we have done here is: Created a group by object called grouped, splitting the dataframe by the Name column, Used the .get_group () method to get the dataframe’s rows that contain ‘Jenny’.Merge DataFrame or named Series objects with a database-style join. A named Series object is treated as a DataFrame with a single named column. The join is done on columns or indexes. If joining columns on columns, the DataFrame indexes will be ignored. Otherwise if joining indexes on indexes or indexes on a column or columns, the index will be ...A DataFrame is a data structure that organizes data into a 2-dimensional table of rows and columns, much like a spreadsheet. DataFrames are one of the most common data structures used in modern data analytics because they are a flexible and intuitive way of storing and working with data.Jul 31, 2015 · In many situations, a custom attribute attached to a pd.DataFrame object is not necessary. In addition, note that pandas-object attributes may not serialize. So pickling will lose this data. Instead, consider creating a dictionary with appropriately named keys and access the dataframe via dfs['some_label']. df = pd.DataFrame() dfs = {'some ... Purely integer-location based indexing for selection by position. .iloc [] is primarily integer position based (from 0 to length-1 of the axis), but may also be used with a boolean array. Allowed inputs are: An integer, e.g. 5. A list or array of integers, e.g. [4, 3, 0]. A slice object with ints, e.g. 1:7. A boolean array.pandas.DataFrame.shape# property DataFrame. shape [source] #. Return a tuple representing the dimensionality of the DataFrame. Divides the values of a DataFrame with the specified value (s), and floor the values. ge () Returns True for values greater than, or equal to the specified value (s), otherwise False. get () Returns the item of the specified key. groupby () Groups the rows/columns into specified groups. 1, or ‘columns’ : Drop columns which contain missing value. Only a single axis is allowed. how{‘any’, ‘all’}, default ‘any’. Determine if row or column is removed from DataFrame, when we have at least one NA or all NA. ‘any’ : If any NA values are present, drop that row or column. ‘all’ : If all values are NA, drop that ...DataFrame.corr (col1, col2 [, method]) Calculates the correlation of two columns of a DataFrame as a double value. DataFrame.count () Returns the number of rows in this DataFrame. DataFrame.cov (col1, col2) Calculate the sample covariance for the given columns, specified by their names, as a double value.labels for the Series and DataFrame objects. It can only contain hashable objects. A pandas Series has one Index; and a DataFrame has two Indexes. # --- get Index from Series and DataFrame idx = s.index idx = df.columns # the column index idx = df.index # the row index # --- Notesome Index attributes b = idx.is_monotonic_decreasingSaving a DataFrame to a Python dictionary dictionary = df.to_dict() Saving a DataFrame to a Python string string = df.to_string() Note: sometimes may be useful for debugging Working with the whole DataFrame Peek at the DataFrame contents df.info() # index & data types n = 4 dfh = df.head(n) # get first n rows DataFrame.nunique(axis=0, dropna=True) [source] #. Count number of distinct elements in specified axis. Return Series with number of distinct elements. Can ignore NaN values. Parameters: axis{0 or ‘index’, 1 or ‘columns’}, default 0. The axis to use. 0 or ‘index’ for row-wise, 1 or ‘columns’ for column-wise. dropnabool, default ... The StructType and StructFields are used to define a schema or its part for the Dataframe. This defines the name, datatype, and nullable flag for each column. StructType object is the collection of StructFields objects. It is a Built-in datatype that contains the list of StructField.Divides the values of a DataFrame with the specified value (s), and floor the values. ge () Returns True for values greater than, or equal to the specified value (s), otherwise False. get () Returns the item of the specified key. groupby () Groups the rows/columns into specified groups. The Pandas len () function returns the length of a dataframe (go figure!). The safest way to determine the number of rows in a dataframe is to count the length of the dataframe’s index. To return the length of the index, write the following code: >> print ( len (df.index)) 18.DataFrame# DataFrame is a 2-dimensional labeled data structure with columns of potentially different types. You can think of it like a spreadsheet or SQL table, or a dict of Series objects. It is generally the most commonly used pandas object. Like Series, DataFrame accepts many different kinds of input: Dict of 1D ndarrays, lists, dicts, or SeriesWhen your DataFrame contains a mixture of data types, DataFrame.values may involve copying data and coercing values to a common dtype, a relatively expensive operation. DataFrame.to_numpy(), being a method, makes it clearer that the returned NumPy array may not be a view on the same data in the DataFrame. Accelerated operations# The DataFrame.index and DataFrame.columns attributes of the DataFrame instance are placed in the query namespace by default, which allows you to treat both the index and columns of the frame as a column in the frame. The identifier index is used for the frame index; you can also use the name of the index to identify it in a query.Dask DataFrame. A Dask DataFrame is a large parallel DataFrame composed of many smaller pandas DataFrames, split along the index. These pandas DataFrames may live on disk for larger-than-memory computing on a single machine, or on many different machines in a cluster. One Dask DataFrame operation triggers many operations on the constituent ... Returns a new DataFrame containing union of rows in this and another DataFrame. unpersist ([blocking]) Marks the DataFrame as non-persistent, and remove all blocks for it from memory and disk. unpivot (ids, values, variableColumnName, …) Unpivot a DataFrame from wide format to long format, optionally leaving identifier columns set. where ... A DataFrame with mixed type columns(e.g., str/object, int64, float32) results in an ndarray of the broadest type that accommodates these mixed types (e.g., object). The DataFrame.index and DataFrame.columns attributes of the DataFrame instance are placed in the query namespace by default, which allows you to treat both the index and columns of the frame as a column in the frame. The identifier index is used for the frame index; you can also use the name of the index to identify it in a query.DataFrame. insert (loc, column, value, allow_duplicates = _NoDefault.no_default) [source] # Insert column into DataFrame at specified location.
pandas.DataFrame.corr# DataFrame. corr (method = 'pearson', min_periods = 1, numeric_only = False) [source] # Compute pairwise correlation of columns, excluding NA .... Who does atandt ship with
Extracting specific rows of a pandas dataframe. df2[1:3] That would return the row with index 1, and 2. The row with index 3 is not included in the extract because that’s how the slicing syntax works. Note also that row with index 1 is the second row. Row with index 2 is the third row and so on. If you’re wondering, the first row of the ... pandas.DataFrame.isin. #. Whether each element in the DataFrame is contained in values. The result will only be true at a location if all the labels match. If values is a Series, that’s the index. If values is a dict, the keys must be the column names, which must match. If values is a DataFrame, then both the index and column labels must match. DataFrame.astype(dtype, copy=None, errors='raise') [source] #. Cast a pandas object to a specified dtype dtype. Parameters: dtypestr, data type, Series or Mapping of column name -> data type. Use a str, numpy.dtype, pandas.ExtensionDtype or Python type to cast entire pandas object to the same type.The DataFrame.index and DataFrame.columns attributes of the DataFrame instance are placed in the query namespace by default, which allows you to treat both the index and columns of the frame as a column in the frame. The identifier index is used for the frame index; you can also use the name of the index to identify it in a query. Marks the DataFrame as non-persistent, and remove all blocks for it from memory and disk. where (condition) where() is an alias for filter(). withColumn (colName, col) Returns a new DataFrame by adding a column or replacing the existing column that has the same name. withColumnRenamed (existing, new) Returns a new DataFrame by renaming an ...DataFrame.set_index(keys, *, drop=True, append=False, inplace=False, verify_integrity=False) [source] #. Set the DataFrame index using existing columns. Set the DataFrame index (row labels) using one or more existing columns or arrays (of the correct length). The index can replace the existing index or expand on it. This parameter can be either ... Returns a new DataFrame containing union of rows in this and another DataFrame. unpersist ([blocking]) Marks the DataFrame as non-persistent, and remove all blocks for it from memory and disk. unpivot (ids, values, variableColumnName, …) Unpivot a DataFrame from wide format to long format, optionally leaving identifier columns set. where ...A Dataframe is a two-dimensional data structure, i.e., data is aligned in a tabular fashion in rows and columns. In dataframe datasets arrange in rows and columns, we can store any number of datasets in a dataframe. We can perform many operations on these datasets like arithmetic operation, columns/rows selection, columns/rows addition etc.pandas.DataFrame.columns# DataFrame. columns # The column labels of the DataFrame. Examples >>> df = pd. pandas.DataFrame.columns# DataFrame. columns # The column labels of the DataFrame. Examples >>> df = pd.pandas.DataFrame.columns# DataFrame. columns # The column labels of the DataFrame. Examples >>> df = pd. pandas.DataFrame.count. #. Count non-NA cells for each column or row. The values None, NaN, NaT, and optionally numpy.inf (depending on pandas.options.mode.use_inf_as_na) are considered NA. If 0 or ‘index’ counts are generated for each column. If 1 or ‘columns’ counts are generated for each row. Include only float, int or boolean data. When your DataFrame contains a mixture of data types, DataFrame.values may involve copying data and coercing values to a common dtype, a relatively expensive operation. DataFrame.to_numpy(), being a method, makes it clearer that the returned NumPy array may not be a view on the same data in the DataFrame. Accelerated operations#DataFrame.corr (col1, col2 [, method]) Calculates the correlation of two columns of a DataFrame as a double value. DataFrame.count () Returns the number of rows in this DataFrame. DataFrame.cov (col1, col2) Calculate the sample covariance for the given columns, specified by their names, as a double value.DataFrame.drop(labels=None, *, axis=0, index=None, columns=None, level=None, inplace=False, errors='raise') [source] #. Drop specified labels from rows or columns. Remove rows or columns by specifying label names and corresponding axis, or by directly specifying index or column names. When using a multi-index, labels on different levels can be ... DataFrame.set_index(keys, *, drop=True, append=False, inplace=False, verify_integrity=False) [source] #. Set the DataFrame index using existing columns. Set the DataFrame index (row labels) using one or more existing columns or arrays (of the correct length). The index can replace the existing index or expand on it. This parameter can be either ... .