Pandas Drop Rows With String

import pandas as pd import numpy as np. Pandas is a vast library. Now we can use pandas drop function to remove few rows. It’s really easy to drop them or replace them with a different value. If you find this small tutorial useful, I encourage you to watch this video, where Wes McKinney give extensive introduction to the time series data analysis with pandas. Pandas KEY We'll use shorthand in this cheat sheet df - A pandas DataFrame object s - A pandas Series object IMPORTS Import these to start import pandas as pd import numpy as np LEARN DATA SCIENCE ONLINE Start Learning For Free - www. Each row was assigned an index of 0 to N-1, where N is the number of rows in the DataFrame. A dataframe is basically a 2d numpy array with rows and columns, that also has labels for columns and rows. Below a picture of a Pandas data frame: What is a Series? A series is a one-dimensional data structure. pandas will automacally preserve observaons as you manipulate variables. How would you do it? pandas makes it easy, but the notation can be confusing and thus difficult. You can think of a hierarchical index as a set of trees of indices. Access them. There are instances where we have to select the rows from a Pandas dataframe by multiple conditions. Based on the excellent @DMulligan's solution, here is a generic vectorized (no loops) function which splits a column of a dataframe into multiple rows, and merges it back to the original dataframe. You can't have two columns with the same name in the merged DataFrame, so pandas adds a '_x' and a '_y' suffix to the overlapping column names. drop() Method. pandas Filter out rows with missing data (NaN, None, NaT) Example If you have a dataframe with missing data ( NaN , pd. Saving a DataFrame to a Python string string = df. Consider the following example: >>> df. subset - optional list of column names to consider. Study 34 Pandas flashcards from Sam Z. Using drop() looks. 832619 2 -0. The iloc indexer syntax is data. Provided by Data Interview Questions, a mailing list for coding and data interview problems. Next, let's get some totals and other values for each month. Pandas makes it very easy to output a DataFrame to Excel. The first thing you probably want to do is see what the data looks like. ' Drop rows with any column having NA/null data. Let's say that you only want to display the rows of a DataFrame which have a certain column value. drop (['job'], axis = 1) In this line of code, we are deleting the column named 'job'. serie geo_props = pd. Let's say that you only want to display the rows of a DataFrame which have a certain column value. Fortunately, it is easy to use the excellent XlsxWriter module to customize and enhance the Excel. If 'all', drop a row only if all its values are null. Here a few ways to check out Pandas data. To create variables by string, you can use - globals() function , which returns the dictionary of global namespace, and then create a new element in that dictionary for your variable and set the value to the value you want. If your rows have numerical indices, you can reference them using iloc. We can see that we have 171,907 rows and 161 columns. Which is listed below. If you find this small tutorial useful, I encourage you to watch this video, where Wes McKinney give extensive introduction to the time series data analysis with pandas. drop) Filtering columns (df. In the dataframe below for example I would like to drop the entirety of row 5 and nothing else, and I don't necessarily know what the strings will be. Lastly, we want to show performance comparison between row-at-a-time UDFs and Pandas UDFs. 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. So, in pandas, we have two ways of dropping the column. Given a Data Frame, we may not be interested in the entire dataset but only in specific rows. To concatenate Pandas DataFrames, usually with similar columns, use pandas. Syntax: DataFrameName. I read a CSV file that has a string column with some missing values, and pandas loads those missing string values as NaN. DataFrame(np. It can read, filter and re-arrange small and large data sets and output them in a range of formats including Excel. pandas Filter out rows with missing data (NaN, None, NaT) Example If you have a dataframe with missing data ( NaN , pd. sort_values() Python Pandas : How to add new columns in a dataFrame using [] or dataframe. DataFrame(np. Study 34 Pandas flashcards from Sam Z. To delete an entire column or row, we can use the drop() method of the DataFrame by specifying the name of the column or row. Remove rows or columns by specifying label names and corresponding axis, or by specifying directly index or column names. For example the following expression produces a boolean array:. Related course: Data Analysis with Python Pandas. I have a DataFrame in which a column might have three kinds of values, integers (12331), integers as strings ('345') or some other string ('text'). Pandas DataFrame by Example Pandas is a very versatile tool for data analysis in Python and you must definitely know how to do, at the bare minimum, simple. Pandas cheat sheet Data can be messy: it often comes from various sources, doesn't have structure or contains errors and missing fields. we can also drop rows that have all NA values:. Pandas dropna() method allows the user to analyze and drop Rows/Columns with Null values in different ways. Drop missing value in Pandas python or Drop rows with NAN/NA in Pandas python can be achieved under multiple scenarios. As the task involves performing some exploratory analysis, I need to decipher what type each Series is. Don't worry, this can be changed later. Apply a function to every row in a pandas dataframe. iloc[pos] Select row by integer position. drop\_duplicates() Drop duplicates by column. NaT , None ) you can filter out incomplete rows. drop_duplicates()", this way will loose column 'd' or. drop¶ DataFrame. reshape(5,2), columns=list('ab. Given a Data Frame, we may not be interested in the entire dataset but only in specific rows. write_row() Saving the Dataframe output to a string; Additional Pandas and Excel Information Data Validation and Drop. To delete rows and columns from DataFrames, Pandas uses the "drop" function. I am dropping rows from a PANDAS dataframe when some of its columns have 0 value. This page is based on a Jupyter/IPython Notebook: download the original. , 'NewCol'). iloc[], we simply use the integer number of the column, starting from the left-most column which is 0. Pandas: Find Rows Where Column/Field Is Null And what if we want to return every row that contains at least one null value? That's not too difficult - it's just a combination of the code. Pandas library is the popular Python package for data science and machine learning, and with good reason: it offers dominant, expressive and flexible data structures that make the data manipulation and analysis effortless, among many other things. tail(n) # get last n rows dfs = df. There are instances where we have to select the rows from a Pandas dataframe by multiple conditions. tail # last five rows df. We saw an example of this in the last blog post. Understand df. Syntax: Series. Syntax: DataFrameName. We are aware of the fact that SQL is a query language primarily used for tabular data analysis. \n ', row) # convert the array to a pandas. #These may simply be a result of my misunderstanding, stumbling though non-optimal / non-pythonic solutions, bad coding, or lack of research, but here are some issues I. In the original dataframe, each row is a. Operating on Null Values. info # memory footprint and datatypes. Also, we will discuss Pandas examples and some terms as ranking, series, panels. Inspecting duplicates. You can vote up the examples you like or vote down the ones you don't like. drop — pandas 0. Also try practice problems to test & improve your skill level. write_rich_string() worksheet. To delete rows and columns from DataFrames, Pandas uses the “drop” function. Based on the excellent @DMulligan's solution, here is a generic vectorized (no loops) function which splits a column of a dataframe into multiple rows, and merges it back to the original dataframe. However, I thought that I might be able to come up with a better solution using pandas. In pandas, the missing values will show up as NaN. saved in its own row Tidy data complements pandas'svectorized Matches strings containing a period '. How set a particular cell value of DataFrame in Pandas? How to select or filter rows from a DataFrame based on values in columns in pandas? Adding new column to existing DataFrame in Pandas; Create an empty DataFrame with Date Index; Drop columns with missing data in Pandas DataFrame; How to convert column with dtype as Int to DateTime in. write_rich_string() worksheet. To drop one or more rows from a Pandas dataframe, we need to specify the row indexes that need to be dropped and axis=0 argument. A regular expression is a special text string for describing a search pattern. \n ', row) # convert the array to a pandas. This functionality is really useful if. This means that if two rows are the same pandas will drop the second row and keep the first row. This seems resonable but I dont know how to concatenate column values from two similar rows? Can you please help. set_index(keys, drop=True, append=False, inplace=False, verify_integrity=False) Set the DataFrame index (row labels) using one or more existing columns. plot in pandas. Don't worry, this can be changed later. Check out this data science tutorial to see an example of how to search for a value in a pandas dataframe. Detailed tutorial on Practical Tutorial on Data Manipulation with Numpy and Pandas in Python to improve your understanding of Machine Learning. DataFrame(Series) - and. Paths to duplicate URLs may need to be cut, too. pandas_cub has a single main object, the DataFrame, to hold all of the data. As we have seen, Pandas treats None and NaN as essentially interchangeable for indicating missing or null values. You may just want to return 1 or 2 or 3 rows or so. There are 1,682 rows (every row must have an index). axis=1 tells Python that you want to apply function on columns instead of rows. filter (self, items=None, like=None, regex=None, axis=None) [source] ¶ Subset rows or columns of dataframe according to labels in the specified index. Here, axis=0 argument specifies we want to drop rows instead of dropping columns. pandas will do this by default if an index is not specified. There are currently 34 videos in the series. But if it proves helpful to any others, great!. Download and unpack the pandas. python with How to drop rows of Pandas DataFrame whose value in certain columns is NaN Calling a function of a module by using its name(a string). DataFrame and pandas. Pandas KEY We'll use shorthand in this cheat sheet df - A pandas DataFrame object s - A pandas Series object IMPORTS Import these to start import pandas as pd import numpy as np LEARN DATA SCIENCE ONLINE Start Learning For Free - www. index or columns can be used from. string_x = "if the df has a lot of rows or columns, then when you try to show the df, pandas will auto detect \ the size of the displaying area and automatically hide some part of the data by replacing with" pd. You can choose to drop the rows only if all of the values in the row are. This means that if two rows are the same pandas will drop the second row and keep the first row. Remove elements of a Series based on specifying the index labels. In this article we will read excel files using Pandas. import modules. Access them. I want to get a new dataframe that is basically the cartesian product of each row with each other row excluding itself: id value id_2 value_2 0 1 a 2 b 1 1 a 3 c 2 2 b 1 a 3 2 b 3 c 4 3 c 1 a 5 3 c 2 b This is my approach as of now. By default yields the new object. I tried to look at pandas documentation but did not immediately find the answer. We can drop a row by column by passing the name of the column we need to delete. Understand df. And here is the list of allowed numpy data types. The syntax for the Pandas Set Index is the following. Databases & SQL. 0 John Smith Note that dropna() drops out all rows containing missing data. 1 documentation Here, the following contents will be described. For example the following expression produces a boolean array:. 0 In this example, we would like to drop the first 4 rows from the data frame. Apr 13, 2017 · I have a very large data frame in python and I want to drop all rows that have a particular string inside a particular column. Suffix labels with string suffix in Pandas series. DataFrame is defined as a standard way to store data that has two different indexes, i. I will be using olive oil data set for this tutorial, you. Introduces Python, pandas, Anaconda, Jupyter Notebook, and the course prerequisites; Explores sample Jupyter Notebooks to showcase the power of pandas for data analysis; The pandas. drop(['A'], axis=1) Column A has been removed. Here are a couple of examples. If we only want to remove one column from the Pandas dataframe we'd input a string (e. Python Pandas DataFrame Tutorial | Data Structure Example In Pandas is today’s topic. Is there an equivalent function for dropping rows with all columns having value 0? P kt b tt mky depth 1 0 0 0 0 0 2 0 0 0 0 0 3 0 0 0 0 0 4 0 0 0 0 0 5 1. Appending of rows is performed using the. Pandas KEY We'll use shorthand in this cheat sheet df - A pandas DataFrame object s - A pandas Series object IMPORTS Import these to start import pandas as pd import numpy as np LEARN DATA SCIENCE ONLINE Start Learning For Free - www. Pandas writes Excel files using the Xlwt module for xls files and the Openpyxl or XlsxWriter modules for xlsx files. Pandas provides a simple way to remove these: the dropna() function. Use drop() to delete rows and columns from pandas. Selecting pandas data using “iloc” The iloc indexer for Pandas Dataframe is used for integer-location based indexing / selection by position. A data frame is a tabular data, with rows to store the information and columns to name the information. For example, if our feature is expected to be a string, but there's a numeric type, then technically this is also a missing value. To drop or remove this row, run the following line of code: >>> df. We can fill them in with a certain value (zero, mean/max/median by column, string) or drop them by row. Given a Data Frame, we may not be interested in the entire dataset but only in specific rows. js are, like in Python pandas, the Series and the DataFrame. Also the argument axis=0 specifies that pandas drop function is being used to drop the rows. Series(row) # for each column, get. Moreover, we will see the features, installation, and dataset in Pandas. If 'all', drop a row only if all its values are null. Or we can define a special string that checks the presence of any punctuation in a text. drop(['A'], axis=1) Column A has been removed. The axis parameter, however, is used to drop columns instead of indices (i. rename) Removing columns (df. I have a pandas dataframe in which one column of text strings contains comma-separated values. Each indexed column/row is identified by a unique sequence of values defining the "path" from the topmost index to the bottom index. dropna(axis = 0, how = 'any') This allows us to drop rows with any missing values in them. There are some reasons for randomly sample our data; for instance, we may have a very large dataset and want to build our models on a smaller sample of the data. Each row in a DataFrame is associated with an index, which is a label that uniquely identifies a row. tail # last five rows df. read_csv) Renaming columns (df. Wouldn’t it be great if we could just skip the boring stuff and work with data? Pandas and SQLAlchemy are a match made in Python heaven. axis=1 tells Python that you want to apply function on columns instead of rows. iloc in Pandas. Python for Machine Learning - Part 7 - Drop Rows and Columns of a Pandas Dataset2 - Duration rows and columns operation like deleting a row or column and getting data frame with the required. Access a single value for a row/column label pair. Dropping rows and columns in pandas dataframe. index or columns can be used from 0. Apply a function to every row in a pandas dataframe. For Series, the row labels are prefixed. Delete rows from DataFr. The pipeline below just use what I consider to be a subset of common operations on dataframe: Creating a dataframe from raw data (we will use an html table with pd. In the dataframe below for example I would like to drop the entirety of row 5 and nothing else, and I don't necessarily know what the strings will be. We can drop a row by column by passing the name of the column we need to delete. The two main objects from Pandas are the Series and DataFrame. It is extremely versatile in its ability to…. sample (5) # random sample of rows df. thresh - int, default None If specified, drop rows that have less than thresh non-null values. pandas documentation: Delete / drop rows from DataFrame. Pandas Set Index Example. drop¶ DataFrame. This can be done with iloc, which is the pandas method for index location. See examples below under iloc[pos] and loc[label]. I have a DataFrame in which a column might have three kinds of values, integers (12331), integers as strings (‘345’) or some other string (‘text’). The method read_excel() reads the data into a Pandas Data Frame, where the first parameter is the filename and the second parameter is the sheet. info() # index & data types n = 4 dfh = df. You can vote up the examples you like or vote down the ones you don't like. We also performed tasks like time sampling, time shifting and rolling with stock data. Paths to duplicate URLs may need to be cut, too. loc[], we specify the column label strings as we have in the earlier exercises in this missions. 1, or 'columns': Drop the columns which contain the missing value. axis=1 tells Python that you want to apply function on columns instead of rows. Part 2: Working with DataFrames, dives a bit deeper into the functionality of DataFrames. Python for Machine Learning - Part 7 - Drop Rows and Columns of a Pandas Dataset2 - Duration rows and columns operation like deleting a row or column and getting data frame with the required. It is built upon the Numpy (to handle numeric data in tabular form) package and has inbuilt data structures to ease-up the process of data manipulation, aka data munging/wrangling. Drop missing value in Pandas python or Drop rows with NAN/NA in Pandas python can be achieved under multiple scenarios. drop() method?. You can think of a hierarchical index as a set of trees of indices. NaT , None ) you can filter out incomplete rows. string_x = "if the df has a lot of rows or columns, then when you try to show the df, pandas will auto detect \ the size of the displaying area and automatically hide some part of the data by replacing with" pd. pandas also provides a variety of methods to work with missing data - some of which would be challenging to express in SAS. For Series, the row labels are suffixed. write_rich_string() worksheet. thresh - int, default None If specified, drop rows that have less than thresh non-null values. Python For Data Science Cheat Sheet Pandas Basics Learn Python for Data Science Interactively at www. It's really easy to drop them or replace them with a different value. There many cases we need to drop a column in the data that represent redundancy in our data or if we implement the machine learning model we need to drop the target feature to train the model on it. zip attachment with the working files for this course is attached to this lesson. Or by integer position if label search fails. If 'all', drop a row only if all its values are null. drop — pandas 0. There are 1,682 rows (every row must have an index). pandas: best way to select all columns whose names start with X; Drop a row and column at the same time Pandas Dataframe; How to filter rows containing a string pattern from a Pandas dataframe; How to test if a string contains one of the substrings in a list, in pandas? Python Pandas Drop Dataframe. Filter using query A data frames columns can be queried with a boolean expression. You can vote up the examples you like or vote down the ones you don't like. Fortunately, it is easy to use the excellent XlsxWriter module to customize and enhance the Excel. From our previous examples, we know that Pandas will detect the empty cell in row seven as a missing value. Remove rows or columns by specifying label names and corresponding axis, or by specifying directly index or column names. It is extremely versatile in its ability to…. To delete an entire column or row, we can use the drop() method of the DataFrame by specifying the name of the column or row. Object columns are used for strings or where a column contains mixed data types. drop_duplicates¶ DataFrame. Summary: If you're working with data in Python, learning pandas will make your life easier! I love teaching pandas, and so I created a video series targeted at beginners. drop(['A'], axis=1) Column A has been removed. Operating on Null Values. In this case, Pandas will create a hierarchical column index () for the new table. Our row indices up to now have been auto-generated by pandas, and are simply integers from 0 to 365. drop() Method. A step-by-step Python code example that shows how to drop duplicate row values in a Pandas DataFrame based on a given column value. dropna(axis = 0, how = 'any') This allows us to drop rows with any missing values in them. Here are a couple of examples. There are some reasons for randomly sample our data; for instance, we may have a very large dataset and want to build our models on a smaller sample of the data. drop¶ Series. Apr 13, 2017 · I have a very large data frame in python and I want to drop all rows that have a particular string inside a particular column. Drop a column in python In pandas, drop( ) function is used to remove column(s). Data Cleansing and Transformation. Drop a variable (column) Note: axis=1 denotes that we are referring to a column, not a row. Is there an equivalent function for dropping rows with all columns having value 0? P kt b tt mky depth 1 0 0 0 0 0 2 0 0 0 0 0 3 0 0 0 0 0 4 0 0 0 0 0 5 1. There are instances where we have to select the rows from a Pandas dataframe by multiple conditions. The DataFrame is capable of holding 4 data types - booleans, integers, floats, and strings. Pandas writes Excel files using the Xlwt module for xls files and the Openpyxl or XlsxWriter modules for xlsx files. 1 documentation Here, the following contents will be described. If you find this small tutorial useful, I encourage you to watch this video, where Wes McKinney give extensive introduction to the time series data analysis with pandas. Let's take a look at the "Owner Occupied" column to see what I'm talking about. add_prefix(self, prefix) Parameters:. 1 Python String Methods Tabular Data and pandas: View the first n rows of a DataFrame or Series: Drop rows or columns with missing values from a DataFrame. So, Dropping the column from DataFrame is an essential task in cleaning the data. drop — pandas 0. Also , you can directly call - pandas. Notes on machine learning and artificial intelligence. drop_duplicates() Similarly, a count of distinct can also be done. Remove rows or columns by specifying label names and corresponding axis, or by specifying directly index or column names. In pandas, the missing values will show up as NaN. Python Pandas DataFrame Tutorial | Data Structure Example In Pandas is today’s topic. drop_duplicates¶ DataFrame. 832619 2 -0. pandas read_csv tutorial. Drop or delete the row in python pandas with conditions In this tutorial we will learn how to drop or delete the row in python pandas by index, delete row by condition in python pandas and delete the row in python pandas by position. pandas is an open source, BSD-licensed library providing high-performance, easy-to-use data structures and data analysis tools for the Python programming language. b) should I create another column and concatenate the values in column 'd' as '2006|2007' and then run "df. 1 Python String Methods Tabular Data and pandas: View the first n rows of a DataFrame or Series: Drop rows or columns with missing values from a DataFrame. Rows or columns can be removed using index label or column name using this method. Sometimes, we have data where the column values are the same and we wish to delete them. txt file with Scanner Class in Java;. The dataset has 10 million rows and 33 columns - but the number of rows grows for a million or so a month. DataFrame(np. If 'all', drop a row only if all its values are null. let's generate a DataFrame first: df = pd. Filter using query A data frames columns can be queried with a boolean expression. import pandas as pd import numpy as np. For Series, the row labels are prefixed. This seems resonable but I dont know how to concatenate column values from two similar rows? Can you please help. Python For Data Science Cheat Sheet Pandas Basics Learn Python for Data Science Interactively at www. Missing value representation. Drop a column in python In pandas, drop( ) function is used to remove column(s). Can this be implemented in an efficient way using. set_index(keys, drop=True, append=False, inplace=False, verify_integrity=False) Set the DataFrame index (row labels) using one or more existing columns. It won't result in information loss, because in the redundant scheme with d columns one of the indicators must be non-zero, so if two out of three are zeros then the third must be 1. There are currently 34 videos in the series. By default yields the new object. I have a DataFrame in which a column might have three kinds of values, integers (12331), integers as strings (‘345’) or some other string (‘text’). Since there are few missing values, we can drop the rows to avoid skewing the data in further analysis. Pandas library is the popular Python package for data science and machine learning, and with good reason: it offers dominant, expressive and flexible data structures that make the data manipulation and analysis effortless, among many other things. , 'NewCol'). Running this will keep one instance of the duplicated row, and remove all those after:. Using last has the opposite effect: the first row is dropped. For DataFrame, the column labels are prefixed. Pandas is a Python module, and Python is the programming language that we're going to use. This functionality is really useful if. apply to send a single column to a function. pandas is an open source, BSD-licensed library providing high-performance, easy-to-use data structures and data analysis tools for the Python programming language. Accessing pandas dataframe columns, rows, and cells At this point you know how to load CSV data in Python. Pandas KEY We'll use shorthand in this cheat sheet df - A pandas DataFrame object s - A pandas Series object IMPORTS Import these to start import pandas as pd import numpy as np LEARN DATA SCIENCE ONLINE Start Learning For Free - www. First, let’s create a DataFrame out of the CSV file ‘BL-Flickr-Images-Book. Apr 13, 2017 · I have a very large data frame in python and I want to drop all rows that have a particular string inside a particular column. #These may simply be a result of my misunderstanding, stumbling though non-optimal / non-pythonic solutions, bad coding, or lack of research, but here are some issues I. If you're unfamiliar with Pandas, it's a data analysis library that uses an efficient, tabular data structure called a Dataframe to represent your data. From our previous examples, we know that Pandas will detect the empty cell in row seven as a missing value. let's generate a DataFrame first: df = pd. Given a dataframe dat with column x which contains nan values,is there a more elegant way to do drop each row of data which has a nan value in the x column. The axis argument is necessary here. I am dropping rows from a PANDAS dataframe when some of its columns have 0 value. pandas documentation: Delete / drop rows from DataFrame. Using String Methods; Changing data type This introduction to pandas is derived from Data School's pandas Q&A with my own notes and code. Pandas pipeline. index [ 2 ]). drop¶ DataFrame. 1 Python String Methods Tabular Data and pandas: View the first n rows of a DataFrame or Series: Drop rows or columns with missing values from a DataFrame. Is there an equivalent function for dropping rows with all columns having value 0? P kt b tt mky depth 1 0 0 0 0 0 2 0 0 0 0 0 3 0 0 0 0 0 4 0 0 0 0 0 5 1. drop() Method. B C D 0 -1. In this post, I am going to discuss the most frequently used pandas features. Pandas: Find Rows Where Column/Field Is Null And what if we want to return every row that contains at least one null value? That's not too difficult - it's just a combination of the code. Syntax: Series. If 'all', drop a row only if all its values are null. Thus, we will get columns named “Unnamed” and “unnamed”. Keep in mind that in Pandas, string data is always stored with an object dtype. Below a picture of a Pandas data frame: What is a Series? A series is a one-dimensional data structure. Pandas read_csv function has various options which help us to take care of certain things like formatting, handling null values etc. Drop duplicate rows in Pandas based on column value; Dropping rows/columns from a Pandas dataframe; Extract month and year from column in Pandas, create new column; Find and replace characters in Pandas dataframe columns; Get row and column count for Pandas dataframe; Get the mean and median from a Pandas column in Python; Iterating over rows. drop all rows that have any NaN (missing) values; drop only if entire row has NaN (missing) values; drop only if a row has more than 2 NaN (missing) values; drop NaN (missing) in a specific column. We can use Pandas drop function to drop rows and columns easily. Below a picture of a Pandas data frame: What is a Series? A series is a one-dimensional data structure. The solution is to drop one of the columns. Pandas has a method specifically for purging these rows called drop_duplicates(). Each row was assigned an index of 0 to N-1, where N is the number of rows in the DataFrame. NET component. index) might be: o Integers - Notefor case or row numbers; o Strings – Notefor case names; or. python with How to drop rows of Pandas DataFrame whose value in certain columns is NaN Calling a function of a module by using its name(a string). axis=1 tells Python that you want to apply function on columns instead of rows. SQL can remove duplicated rows of data by SELECT DISTINCT column1, column2 FROM table_name. com Pandas DataCamp Learn Python for Data Science Interactively. For Series, the row labels are prefixed.