Dataframe Row With Max Value In Column

4674780 2 1. For example, the following code extracts all columns for the first three rows of the data frame (the light-shaded candies with a pattern). but after grouping, I want to get the row with the minimum 'c' value, grouped by column 'a' and display that full matching row in result like, 196512 118910 12. sum Return the sum over the requested axis. Column And Row Sums In Pandas And Numpy. This is a form of data selection. Append column to Data Frame (or RDD). We can apply the filter operation on Purchase column in train DataFrame to filter out the rows with values more than 15000. format() method. To simulate the select unique col_1, col_2 of SQL you can use DataFrame. The Data Frame in R is a table or two dimensional data structure. Python Pandas Tutorial: DataFrame Basics Get a tuple of the number of rows and columns of the DataFrame using the shape (cumulative max): Value of the row is replaced by the maximum value. Select the minimum values of first cell or all cells. converting character vectors to factors). A row was inserted above the Start row, and it will create spacing at the left of the chart. If there are records in the "Orders" table that do not have matches in "Customers", these orders will not be shown!. You will find a handful of formula examples to lookup values to left, search by row and column values, lookup with multiple criteria, and more. pandas: Adding a column to a DataFrame (based on another DataFrame) Nathan and I have been working on the Titanic Kaggle problem using the pandas data analysis library and one thing we wanted to do was add a column to a DataFrame indicating if someone survived. It is also possible to show a subset of variables or plot different variables on the rows and columns. if there are duplicate values in a particular column of your DataFrame. SQLite uses a more general dynamic type system. Returns or sets the background color of the non-fixed cells. Special thanks to Bob Haffner for pointing out a better way of doing it. So the update has trully materialized the default value in the row image. frame, and will be used as the layer data. We can check the data type of a column either using dictionary like syntax or by adding the column name using DataFrame. One difference is that if we try to get a single row of the data frame, we get back a data frame with one row, rather than a vector. A similar question is asked here: Python : How can I get the Row which has the max value in goups making groupby? However, I just need one record per group even if there are more than one record with maximum value in that group. The SQL INSERT INTO syntax has 2 main forms and the result of either of them is adding a new row into the database table. But if we directly apply the PATH function in each row, we will not get the intended results as you can see in the image below. In this article, you will learn how to use min and max in R. You can define a name to refer to a range whose size varies depending on its contents. I don't know which column the values are in but I do know the label of the column. The important part is indexing by logical criteria. idxmin Return the index of the minimum. Select DataFrame Rows Based on multiple conditions on columns. At this point you will be able to see the max length of the values in the columns with the formula entered. iloc[2,6] which gives output 'F' Remember that Python indexing begins at 0. raw download clone embed report print C++ 8. filter out rows in Pandas multi-level index dataframe I am trying to filter out rows in a Pandas dataframe based on two columns. ) but wants to perform a logistic regression model with a binary variable. Select rows when columns contain # Import modules import pandas as pd # Set ipython's max row #Grab DataFrame rows where column has certain values df [df. a logical value or a numeric vector. Internally, columns are stored as 1d numpy arrays. In this case, the levels were automatically assigned alphabetically (when creating the data frame), so large is first and small is last. Does that make sense? Please cc me if you reply! Chris. Full Update. If the input is a dataframe, then the method will return a series with maximum of values over the specified axis in the dataframe. frame, and will be used as the layer data. If you have Parallel Computing Toolbox™, create a 1000-by-1000 distributed array of random numbers with underlying data type single. Still there are certain summary columns like "count of unique values" which are not available in above dataframe. frame, and will be used as the layer data. Filter multiple rows using isin in DataFrame; How to generate demo on a randomly generated DataFrame? How to Import CSV to pandas with specific Index? Pandas Count distinct Values of one column depend on another column; How to append rows in a pandas DataFrame using a for loop? Forward and backward filling of missing values of DataFrame columns. • CC BY RStudio • [email protected] First, let’s define a dataframe with more than one max value: Now, we use logical indexing to find all maxima: This will give you all the values in all rows where your ‘one’ column has its max value, you can slice and dice this to taste. Output of data_frame. A row was inserted above the Start row, and it will create spacing at the left of the chart. We cannot drop single values from a DataFrame; we can only drop full rows or full columns. converting character vectors to factors). How would I go about changing a value in row x column y of a dataframe? In pandas this would be df. To find, say, the maximum value of the Discovered column (which we know contains missing values), you can use the complete_cases() function. (1,2,3 and 4) I don't know which values are in Column B so I can't specify this in my query. It lets you store huge amounts of numerical data, and easily manipulate that data from NumPy. Apache Spark is generally known as a fast, general and open-source engine for big data processing, with built-in modules for streaming, SQL, machine learning and graph. DataFrame (raw_data, columns = # Index of the row with the highest value in the preTestScore column df. This way uses the contains method. Keep a range of rows. Robert Sheldon explains how to get started using the data frame object, how to pass data from SQL Server to it. Consider this dataset. ,1,2,3) it only returns the 183 three times. All the methods you have described are perfect for finding the largest value in a Spark dataframe column. We have two dimensions – i. frame is a generic function with many methods, and users and packages can supply further methods. Get row index label or position of maximum values of every column DataFrame. vector will work as the method. data frame sort orders. Create summaries of the data frame using summarise() The summarise() function will create summary statistics for a given column in the data frame such as finding the mean. frozenset []. drop_duplicates(): df. The first syntax form of the INSERT INTO SQL clause doesn't specify the column names where the data will be inserted, but just their values:. You will also learn how to remove rows with missing values in a given column. For example, you can slice into multi-terabyte datasets stored on disk, as if they were real NumPy arrays. Performance and compact code are essential. Dear R users, I wonder how I can use R to identify the max value of each row, the column number column name: For example: a. May 11, 2017 · I have a data frame in pyspark. , variables). In lesson 01, we read a CSV into a python Pandas DataFrame. How to Update a Column Based on a Filter of Another Column Data Tutorial SQL Tips. Each row in the matrix specifies the location of one value, where each column corresponds to a dimension in the array being subsetted. in our case > order(c(1,4,1,2,1)) [1] 1 3 5 4 2 If we pass a collection of indices to the extract operation it'll reorder the rows. We cannot drop single values from a DataFrame; we can only drop full rows or full columns. In this section, we will learn how to reverse Pandas dataframe by column. Adding and removing columns from a data frame Problem. Therefore, the function used here to compute column means (averages) is named colAvgs. How to select rows from a DataFrame based on values in some column in pandas? In SQL I would use: select * from table where colume_name = some_value. All data frames have a row names attribute, a character vector of length the number of rows with no duplicates nor missing values. argmax() or import numpy as np max_row = np. Additionally, I had to add the correct cuisine to every row. take() twice, converting to Pandas and slicing, etc. Find largest value in a dataframe column. 8983353775637 196795 28978 12. First, take the log base 2 of your dataframe, apply is fine but you can pass a DataFrame to numpy functions. frame, and will be used as the layer data. Arrays are sequence types and behave very much like lists, except that the type of objects stored in them is constrained. A growing list of extensions and plugins is available on the wiki. min() - Returns the lowest value in each column df. The columns of the data frame can be accessed using integer subscripts or the column name and the $ symbol. You can use the steps in this article for any query where you need to select rows with MAX value for a column in Oracle SQL. It is a data manipulation toolbox similar to R data. If you have an analysis to perform I hope that you will be able to find the commands you need here and copy/paste. In this lesson, you will learn how to access rows, columns, cells, and subsets of rows and columns from a pandas dataframe. How do I highlight the lowest value in each row and column with conditional formatting function. If you ensure that your data is tidy, you’ll spend less time fighting with the tools and more time working on your analysis. I have written the program below, but I am struggling to get it to work automatically, without having to manually add in the number of columns in the max() function on line 3 - plea. Highlight the range that you want to select the smallest values. How can I get the number of missing value in each row in Pandas dataframe. OpenRefine can be used to link and extend your dataset with various webservices. In this tutorial we will learn how to select row with maximum and minimum value in python pandas. Rows and columns of cells may be organized into row groups and column groups. If a list is supplied, each element is converted to a column in the data frame. Python functions [20 exercises with solution] Example : The first perfect number is 6, because 1, 2, and 3 are its proper positive divisors, and 1 + 2 + 3 = 6. Columns must be given in the order of the dataset. (Scala-specific) Returns a new DataFrame where a single column has been expanded to zero or more rows by the provided function. How to select rows from a DataFrame based on values in some column in pandas? In SQL I would use: select * from table where colume_name = some_value. I have this much code which does not work. ID 1001 - Value 70. In the applied function, you can first transform the row into a boolean array using between method or with standard relational operators, and then count the True values of the boolean array with sum method. Other data structures, like DataFrame and Panel, follow the dict-like convention of iterating over the keys of the objects. Drop a row if it contains a certain value (in this case, "Tina") Specifically: Create a new dataframe called df that includes all rows where the value of a cell in the name column does not equal "Tina". looking at the picture, i want 1423 in all rows. 5625 Click me to see the sample solution. This is similar to a LATERAL VIEW in HiveQL. A growing list of extensions and plugins is available on the wiki. In this article, we will show how to retrieve a row or multiple rows from a pandas DataFrame object in Python. Select the minimum values of first cell or all cells. , variables). Aggregate functions, such as the MAX function, can cause the same calculation to repeat for every row. The best way to get this into all the additional columns would be to simply copy and paste. own functions across all values in a column (or row) looking line plot using the maximum temperature column from our DataFrame. Each value belongs to one data type. The first thing that R stores is a list of names which refer to each column of the data. frozenset []. The column of interest can be. Sort index. name value 3 dave 1 5 john 1 1 paul 1 4 will 2 2 mark 4 To do that we can use the order function which will tell us the indices of the vector in sorted order. Our food production data contains 21,477 rows, each with 63 columns as seen by the output of. To call a function for each row in an R data frame, we shall use R apply function. The Data Frame in R is a table or two dimensional data structure. How would you do it? pandas makes it easy, but the notation can be confusing and thus difficult. max() function returns the maximum of the values in the given object. Pandas Set Index Example | Python DataFrame. I have a large data set (4. 解决python - Pandas Dataframe Add a value to a new Column based on the previous row limited to the maximum value in that column 分享于 2019阿里云双11. 5625 Click me to see the sample solution. max_rows") Its output is as follows −. the lookup columns in both data frames have the same name, and both data frames have the same number of rows (one per column), making this. Hello Friends, Have you ever been in a situation where you as a developer knows that your data is stored in your table rows, but you would like to present the data as a column ??. To call a function for each row in an R data frame, we shall use R apply function. So, if I had a simple table like in the. The above code will retrieve all rows for which the My_Date column value is equal to the maximum value of My_Date for that user_id. Connecting SQLite to the Database. I'm trying to write a DAX function to find the maximum value in one column based on a condition in another, but have this condition change dynamically based on the row value. We compare this to the remove() method on list, which searches for the first matching value and then deletes it. Get the index of maximum value in DataFrame column Pandas DataFrame is two-dimensional size-mutable, potentially heterogeneous tabular data structure with labeled axes (rows and columns). Most of the times when you are working with data frames, you are changing the data and one of the several changes you can do to a data frame is adding column or row and as the result increase the dimension of your data frame. If a list or data frame or matrix is passed to data. Home » Python » Filter dataframe rows if value in column is in a set list of values Filter dataframe rows if value in column is in a set list of values Posted by: admin October 29, 2017 Leave a comment. variable mycol does not exist as a column name of DT so R then looked in the calling scope and found mycol there and returned its value "x". Row names (such as plot IDs) can also added if desired, using the row. I am dropping rows from a PANDAS dataframe when some of its columns have 0 value. Items that can be referenced by a name, such as SQL parameters, columns, fields, attributes, and variables, also have declared types. Expatica is the international community’s online home away from home. dropna(how = ' all ') # drop a row only if ALL values are missing # fill in missing values. Numpy_Example_List_With_Doc has these examples interleaved with the built-in documentation, but is not as regularly updated as this page. 2 >>> df['sum'. • purrr enhances R’s functional programming (FP) toolkit by providing a complete and consistent set of tools for working with functions and vectors. I am trying out using pandas+sqlalchemy (specifically sqlite) as a means to store my data. In this example, we'll learn step-by-step how to select the variables, paramaters and desired values for outlier elimination. The function stdev computes the standard deviation for a vector or matrix and was introduced for SPlus compatibility. Finally, the rows are numbered consecutively from 1 to 54. By default, this label is just the row number. 7805170314276 196346 28980 12. Flatten hierarchical indices created by groupby. If the input is a series, the method will return a scalar which will be the maximum of the values in the series. It shows us minimum, maximum, average, standard deviation as well as quantile values with respect to each numeric column. Calculate percentage of NaN values in a Pandas Dataframe for each column. Edit: I wrote this reply before seeing the previous post. sum() Sum of all of the Land Average Temperatures. Suppose I have the data frame: table R data frame with values conditional on another column. Aggregate always returns a data. The following example uses the MAX function to find the largest population in the SQL. loc[df['Value']. It is a data manipulation toolbox similar to R data. You may use the following Python code to create the DataFrame:. Very frequently, you will need to return a row or column of values from the table the row or column position in the table, or you may need to return a value from the table based upon a match of values in the row headers and column headers. Selecting pandas dataFrame rows based on conditions. 15 Easy Solutions To Your Data Frame Problems In R Discover how to create a data frame in R, change column and row names, access values, attach data frames, apply functions and much more. def split_data_frame_list (df, target_column, output_type = float): ''' Accepts a column with multiple types and splits list variables to several rows. The following are the some of the characteristics of the Data Frame: In this example, we will create. In lesson 01, we read a CSV into a python Pandas DataFrame. sort_index() Select Rows & Columns by Name or Index in DataFrame using loc & iloc | Python Pandas; Pandas: Sort rows or columns in Dataframe based on values using Dataframe. argmax() or import numpy as np max_row = np. The best way to get this into all the additional columns would be to simply copy and paste. df ['new_column'] = 23. And it comes :P [code]import pandas as pd #create a df s = "This answer is written by Gaurav" ls = s. count() Returns the number of non-null values in each DataFrame column: df. DataFrame (raw_data, columns = # Index of the row with the highest value in the preTestScore column df. My output should ideally be this:. In the same manner as we calculated the bonuses for the last N months, you can get an average of the last N days, weeks or years as well as find their maximum or minimum values. DataFrameNaFunctions Methods for handling missing data (null values). How can I get the number of missing value in each row in Pandas dataframe. frames in Python - DataMatrix. frame will contain the (now unique) values from the input parameter by as the first column and then columns containing the results of the call to the function in the FUN parameter applied to the parts of the columns of the inputted data. Removing rows by the row index 2. You can use the following syntax to get the count of values for each column: df. max & min values within dataframe. In this article, you will learn how to use min and max in R. vector will work as the method. In this tutorial, you will learn how to select or subset data frame columns by names and position using the R function select() and pull() [in dplyr package]. By default, Prophet uses a linear model for its forecast. Similarly, use the functions rowMeans() and colMeans() to calculate means. If None, the maximum data value in the column to be plotted is used. Excel 2003 and earlier versions are limited to 65,536 rows of data. The dataframe package is part of the Octave Forge project. • purrr enhances R’s functional programming (FP) toolkit by providing a complete and consistent set of tools for working with functions and vectors. Aggregate functions, such as the MAX function, can cause the same calculation to repeat for every row. How to sort pandas data frame by a column,multiple columns, and row? Often you want to sort Pandas data frame in a specific way. Rows and columns of cells may be organized into row groups and column groups. I actually have a dataframe with in the column Plotting Fold change (FC) inside genomic interval I would like to select specific rows in a dataframe when I get a value in some row. pandas: Adding a column to a DataFrame (based on another DataFrame) Nathan and I have been working on the Titanic Kaggle problem using the pandas data analysis library and one thing we wanted to do was add a column to a DataFrame indicating if someone survived. As with a matrix, a data frame can be accessed by row and column with [,]. If there are records in the "Orders" table that do not have matches in "Customers", these orders will not be shown!. finding max value in a row and reporting colum name. See fortify() for which variables will be created. And it comes :P [code]import pandas as pd #create a df s = "This answer is written by Gaurav" ls = s. max_column This is all very good, but I can almost hear you thinking now that this seems to be an awfully hard way to work with these files, especially if you want to still manipulate the data. Unlike python lists or dictionaries and just like NumPy, a column of the DataFrame will always be of same type. Introduction to C Programming Arrays Overview. Methods 2 and 3 are almost the same in terms of physical and logical plans. max Return the maximum over the. If your data had only one column, ndim would return 1. If you've used R or even the pandas library with Python you are probably already familiar with the concept of DataFrames. Store the log base 2 dataframe so you can use its subtract method. This is because the row may contain data of different types, and a vector can only hold elements of all the same type. MAX on rows *and* columns. The default value is Integer. COUNT counts rows with non-null values, AVG averages non-null values, and so on. read_csv('test. Data frames are the only backend that supports creating a variable and using it in the same summary. Robert Sheldon explains how to get started using the data frame object, how to pass data from SQL Server to it. I would like a DataFrame where each column in df1 is created but replaced with cat_codes. I would like to get with a excel formula (No VBA) the header of the column and of the row that contain the max value in a table. Most of the times when you are working with data frames, you are changing the data and one of the several changes you can do to a data frame is adding column or row and as the result increase the dimension of your data frame. Instead (as everyone reading this obviously knows), we have to specify DF[2:5,]. When using iat(), both arguments need to be integer positions of the row and column respectively. nsmallest¶ DataFrame. We cannot use del to search for a value. For maximum flexibility, generate the source code to a separate file which you can input from your main document file with the \input command. All-null set or column Other sets or columns; COUNT (*) 0: Total number of rows: Total number of rows: COUNT (Field) 0: 0: Number of rows where Field is not NULL: MAX, MIN: NULL: NULL: Max or min value found in the column: SUM: NULL: NULL: Sum of non-NULL values in the column AVG: NULL: NULL. Edit 27th Sept 2016: Added filtering using integer indexes There are 2 ways to remove rows in Python: 1. max(My_Date) over (partition by user_id) max_My_Date. sort_index() Select Rows & Columns by Name or Index in DataFrame using loc & iloc | Python Pandas; Pandas: Sort rows or columns in Dataframe based on values using Dataframe. assign() Pandas : Sort a DataFrame based on column names or row index labels using Dataframe. For example, a data frame may contain many lists, and each list might be a list of factors, strings, or numbers. Some columns can be omitted, empty values will be inserted instead. ) a data frame, a matrix-like stucture whose columns may be of differing types (numeric, factor and character). We'll use 'Weight' and 'Salary' columns of this. This page is based on a Jupyter/IPython Notebook: download the original. In pandas data frames, each row also has a name. In the applied function, you can first transform the row into a boolean array using between method or with standard relational operators, and then count the True values of the boolean array with sum method. Tip: To use del on a list we must specify an index or a slice. This is because the row may contain data of different types, and a vector can only hold elements of all the same type. Similarly, each column of a matrix is converted separately. List-columns and the data frame that hosts them require some special handling. 7805170314276 196346 28980 12. The following example illustrates a possible problem when extracting the class of columns in a data frame: if you falsely assume that class only has one value and use sapply(), you won’t find out about the problem until some future function is given a list instead of a character vector. This page describes VBA code to import large text files into Excel. You will also learn how to remove rows with missing values in a given column. In this data frame I have column called id that is unique. Returns or sets the background color of the area not covered by any cells. While the chain of. Pandas: Find maximum values & position in columns or rows of a Dataframe; numpy. Ways to iterate over rows. You can use the following syntax to get the count of values for each column: df. [code]# imports import pandas as pd import numpy as np # set random seed for reproducible data np. This package permits to handle complex (both in the sense of complex numbers and high complexity) data as if they were ordinary arrays, except that each column MAY possess a different type. 445 Commonalities. Drop a row if it contains a certain value (in this case, "Tina") Specifically: Create a new dataframe called df that includes all rows where the value of a cell in the name column does not equal "Tina". Let's say you have a table called sales_volume that looks like this:. A second vector, v2, is composed of five logical values drawn of type T and F. requires a 2-D array Z that speci es function values on a grid. We set the column 'name' as our index. This statement uses the MAX() to get the largest payment of each customer:. To simulate the select unique col_1, col_2 of SQL you can use DataFrame. Selecting rows and columns in a DataFrame. This is a way to take many vectors of different types and store them in the same variable. I have written the program below, but I am struggling to get it to work automatically, without having to manually add in the number of columns in the max() function on line 3 - plea. One difference is that if we try to get a single row of the data frame, we get back a data frame with one row, rather than a vector. If we look at the values in the dataframe, we can verify the result returned by the function. Pandas DataFrame is two-dimensional size-mutable, potentially heterogeneous tabular data structure with labeled axes (rows and columns). First, let’s define a dataframe with more than one max value: Now, we use logical indexing to find all maxima: This will give you all the values in all rows where your ‘one’ column has its max value, you can slice and dice this to taste. table package. Rank the dataframe in python pandas - (min, max, dense & rank by group) In this tutorial we will learn how to rank the dataframe in python pandas by ascending and descending order with maximum rank value, minimum rank value , average rank value and dense rank. The easiest way to do this is to use the functions rowSums() and colSums(). MAX_VALUE by default so that the network will fill the chunk size defined by hbase. Nov 16, 2016 · How do I find all rows in a pandas dataframe which have the max value for count column, after grouping by ['Sp','Mt'] columns? How do I find all rows in a pandas. # get the maximum values of all the column in dataframe df. What "Apply" does Lapply and sapply: avoiding loops on lists and data frames Tapply: avoiding loops when applying a function to subsets "Apply" functions keep you from having to write loops to perform some operation on every row or every column of a matrix or data frame, or on every element in a list. If you have an analysis to perform I hope that you will be able to find the commands you need here and copy/paste. Working with data in a matrix Loading data. A similar question is asked here: Python : How can I get the Row which has the max value in goups making groupby? However, I just need one record per group even if there are more than one record with maximum value in that group. We'll use 'Weight' and 'Salary' columns of this. 7805170314276 196346 28980 12. They keep the features that have stood the test of time, and drop the features that used to be convenient but are now frustrating (i. Create summaries of the data frame using summarise() The summarise() function will create summary statistics for a given column in the data frame such as finding the mean. To call a function for each row in an R data frame, we shall use R apply function. filter() picks cases based on their values. The last datatypes of each column, but not necessarily in the corresponding order to the listed columns. If your data had only one column, ndim would return 1. OpenRefine can be used to link and extend your dataset with various webservices. Split a list of values into columns of a dataframe? That is each unique value becomes a column in the df. Interpreter reads this value and displays the rows with this value as upper limit to display. Typically, one may want to sort pandas data frame based on the values of one or more columns or sort based on the values of row index or row names of pandas dataframe. We cannot use del to search for a value. Pandas DataFrame is a 2-D labeled data structure with columns of a potentially different type. Get the entire row which has the maximum value of a column in python pandas. the lookup columns in both data frames have the same name, and both data frames have the same number of rows (one per column), making this. A fellow SQL Server Developer was wondering if it was possible to find the MAX and MIN values of multiple rows and columns and then compare it to a value on a single row. Syntax 1 allows the insertion of a single row with the specified expression values. In addition to finding the exact value, you can also query a dataframe column's value using a familiar SQL like clause. I did try this on my own and searched the board for help, but I couldn't seem to find something that applied. The predict method will assign each row in future a predicted value which it names yhat. The subsequent arguments describe what to do with it, and you can refer to columns in the data frame directly without using $. find max value in each row and return column number and column name. The first two are ways to apply column-wise functions on a dataframe column: use_column: use pandas column. drop_duplicates(): df. No problem :) If you want the exact output as shown in your example you can use the following SQL query to create a Power Pivot table: WITH CTE_MaxRev AS ( SELECT ID, MAX(Rev) OVER (PARTITION BY ID) AS MaxRev FROM #Table AS t2 ) SELECT ID, Rev, [Duration Time] FROM #Table AS t1 WHERE EXISTS ( SELECT ID, MaxRev FROM CTE_MaxRev AS mr WHERE t1. def split_data_frame_list (df, target_column, output_type = float): ''' Accepts a column with multiple types and splits list variables to several rows. In total, I compared 8 methods to generate a new column of values based on an existing column (requires a single iteration on the entire column/array of values). Home » Python » count the frequency that a value occurs in a dataframe column count the frequency that a value occurs in a dataframe column Posted by: admin November 24, 2017 Leave a comment. The above code will retrieve all rows for which the My_Date column value is equal to the maximum value of My_Date for that user_id. Provides comprehensive information about the Base SAS data set options. In R Data Frames, data is stored in row and columns, and we can access the data frame elements using the row index and column index. This is because the row may contain data of different types, and a vector can only hold elements of all the same type. The diagonal Axes are treated differently, drawing a plot to show the univariate distribution of the data for the variable in that column. We'll use 'Weight' and 'Salary' columns of this. There are many different ways of adding and removing columns from a data frame. from users) where My_Date = max_My_Date. Tip: To use del on a list we must specify an index or a slice.