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Pandas is one of the most popular python library for data analysis and data wrangling. In this article we will see how we can create a pandas dataframe and then delete some selective rows ort columns from this data frame.

Deleting roews

In the below example we have the chúng tôi file which is read into a data frame. We first have a look at the existing data frame and then apply the drop function to the index column by supplying the value we want to drop. As we can see at the bottom of the result set the number of rows has been reduced by 3.

Example import pandas as pd # making data frame from csv file data = pd.read_csv("E:iris1.csv",index_col ="Id") print(data) # dropping passed values data.drop([6,9,10],inplace=True) # display print(data) Output

Running the above code gives us the following result −

   SepalLengthCm    SepalWidthCm    PetalLengthCm    PetalWidthCm    Species Id 1    5.1                3.5             1.4             0.2       Iris-setosa 2    4.9                3.0             1.4             0.2       Iris-setosa 3    4.7                3.2             1.3             0.2       Iris-setosa .   ..   …   .…   .…..…… [150 rows x 5 columns] After Dropping    SepalLengthCm    SepalWidthCm    PetalLengthCm    PetalWidthCm    Species Id 1      5.1                3.5             1.4             0.2       Iris-setosa 2      4.9                3.0             1.4             0.2       Iris-setosa 3      4.7                3.2             1.3             0.2       Iris-setosa 149    6.2                3.4             5.4             2.3       Iris-virginica 150    5.9                3.0             5.1             1.8       Iris-virginica …………………. [147 rows x 5 columns] Dropping Columns

For dropping the columns form a pandas data frame, we use the axis parameter. Its value is set to one in the drop function and we supply the column names to be dropped. As you can see the number of columns in the result set gets reduced from 5 to 3.

Example import pandas as pd # making data frame from csv file data = pd.read_csv("E:iris1.csv",index_col ="Id") print(data) # dropping passed values data.drop(['SepalWidthCm','PetalLengthCm'],axis=1,inplace=True) print("After Dropping") # display print(data) Output

Running the above code gives us the following result −

   SepalLengthCm    SepalWidthCm    PetalLengthCm    PetalWidthCm    Species Id 1       5.1          3.5                1.4             0.2          Iris-setosa 2       4.9          3.0                1.4             0.2          Iris-setosa 3       4.7          3.2                1.3             0.2          Iris-setosa .   .   .…   .…   .….   .…… [150 rows x 5 columns] After Dropping    SepalLengthCm    PetalWidthCm    Species Id 1    5.1             0.2             Iris-setosa 2    4.9             0.2             Iris-setosa 3    4.7             0.2             Iris-setosa .....…. [150 rows x 3 columns]

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How To Add Header Row To A Pandas Dataframe?

Pandas is a super popular data handling and manipulation library in Python which is frequently used in data analysis and data pre-processing. The Pandas library features a powerful data structure called the Pandas dataframe, which is used to store any kind of two-dimensional data. In this article we will learn about various ways to add a header row (or simply column names) to a Pandas dataframe.

NOTE − The code in this article was tested on a jupyter notebook.

We will see how to add header rows in 5 different ways −

Adding header rows when creating a dataframe with a dictionary

Adding header rows when creating a dataframe with a list of lists

Adding header rows after creating the dataframe

Adding header rows when reading files from a CSV

Adding header rows using set_axis method

Let’s begin by importing Pandas

import pandas as pd Method 1: When creating a dataframe with a dictionary Example # Add header row while creating the dataframe through a dictionary data = {'course': ['Math', 'English', 'History', 'Science', 'Physics'], 'instructor': ['John Smith', 'Sarah Johnson', 'Mike Brown', 'Karen Lee', 'David Kim'], 'batch_size': [43, 25, 19, 51, 48] } df1 = pd.DataFrame(data) df1 Output course instructor batch_size 0 Math John Smith 43 1 English Sarah Johnson 25 2 History Mike Brown 19 3 Science Karen Lee 51 4 Physics David Kim 48 Method 2: When creating a dataframe with list of lists Example # Add header row while creating the dataframe through lists data = [['apple', 'red', 5], ['banana', 'yellow', 12]] columns = ['fruit', 'color', 'quantity'] df2 = pd.DataFrame(data, columns=columns) df2 Output fruit color quantity 0 apple red 5 1 banana yellow 12

In this method, we have a list of lists where each sub-list stores the information for the rows of the dataframe. We make a list of column names and pass it to the pd.DataFrame method while initializing the dataframe.

Method 3: After creating the dataframe Example # Add header row after creating the dataframe data = [['apple', 'red', 5], ['banana', 'yellow', 12]] columns = ['fruit', 'color', 'quantity'] df3 = pd.DataFrame(data) df3.columns = columns df3 Output fruit color quantity 0 apple red 5 1 banana yellow 12

In the code above we first initialize a dataframe without any header rows. Then we initialize a list of column names we want to use and use the pd.DataFrame.columns attribute to set the header rows of the already defined Pandas dataframe.

Method 4: When reading files from a CSV file Example

When trying to read a CSV file using Pandas, it automatically considers the first row as the column names. However it is likely there is no column name present in our dataset as shown in the example below. Let’s assume the dataset is stored as ‘course_data.csv’.

# Incorrect header row df4 = pd.read_csv('course_data.csv') df4 Output Math John Smith 43 0 English Sarah Johnson 25 1 History Mike Brown 19 2 Science Karen Lee 51 3 Physics David Kim 48

The output shows that Pandas is interpreting a data sample as the header row. To tackle this, we will specify the column names by passing a list of header row names through the ‘names’ argument.

Example # Add header row while reading files from CSV columns = ['course', 'instructor', 'batch_size'] df4 = pd.read_csv('course_data.csv', names=columns) df4 Output course instructor batch_size 0 Math John Smith 43 1 English Sarah Johnson 25 2 History Mike Brown 19 3 Science Karen Lee 51 4 Physics David Kim 48

As shown in the output above, Pandas is no longer reading the first data sample as a header row!

Method 5: Using set_axis method Example

We already saw how to add header rows to an existing dataframe in Method 2. Now we will achieve the same using the pd.DataFrame.set_axis method.

# Add row row after creating the dataframe using set_axis data = [['dog', 'brown', 4], ['cat', 'white', 4], ['chicken', 'white', 2]] df5 = pd.DataFrame(data) columns = ['animal', 'color', 'num_legs'] df5.set_axis(columns, axis=1, inplace=True) df5 Output animal color num_legs 0 dog brown 4 1 cat white 4 2 chicken white 2

Here first we initialize a dataframe without any header rows using the data above. Then we use the set_axis method to add the header rows. We pass axis=1 to specify that we are setting the column names. We also set the flag, ‘inplace’ to be True to do in-place.

NOTE − Setting axis = 0 would set row-names instead of column-names and may also throw errors since there are usually more rows than columns.

Conclusion

This article taught us how to add headers to dataframes in Pandas. We saw 5 different ways to do so which can be used in various different applications and projects.

How To Delete Files From Your Mac That Won’t Delete

How to Delete Files from Your Mac that Won’t Delete

Here in this post, we will cover ways to delete files from your Mac that refuse to be moved to Bin.

Disclaimer – The steps explained below will help remove third-party apps. If you are facing a problem in uninstalling any pre-installed app, we suggest you contact the corresponding developer or can contact Apple support.

Fix – “File in Use” Error

2. Select “Force Quit.”

3. Review the apps and locate the one, you want to move to trash.

5. Once the app is exited, try moving the app to Bin.

6. It should now move to Bin without giving the File in Use error message.

1. Writer’s Tip:

There can be several reasons for uninstalling an app and most of us think dragging the app to the Trash Bin is enough. Well, that’s certainly not enough! Because manually moving an app to Bin doesn’t remove all corresponding files (in most cases).

Therefore, the best way to uninstall an application along with its belonging files is to use the top uninstall manager. Fortunately, we have an app that helps do it and it is called Cleanup My System.

Using its Uninstall Manager module, you can easily uninstall an app from your system.

To use it, follow these steps:

1. Download and install Cleanup My System on your macOS.

2. Navigate to the Uninstall Manager module from the left pane.

3. A list of all the installed applications will prompt on your screen under different categories.

4. Select the app you want to delete and hit the Uninstall button.

5. That’s it, this way you can easily remove an app and its associated files from your Mac.

Alongside this, you can also check out the list of best uninstall managers for Mac covered by us.

This is it, using these simple steps, you can delete files that won’t get deleted. We hope you managed to move the apps to Bin using the steps explained above.

Now that the files are deleted, you won’t want them to sit in the Bin and eat up storage space, right? The best way to avoid this is to empty trash. In addition to this, you can also remove junk files and other unwanted data that take unnecessary space.

For this, you can try using Cleanup My System. The best Mac optimization utility that helps clean junk files, identify large and old files. Also, it helps empty trash without any issues.

To use it follow these steps:

1. Download and install Cleanup My System.

2. Launch the Mac cleanup tool.

5. Select the files you want to remove permanently from your Mac and hit the Clean Now button.

Alongside, you can also use other modules provided by Cleanup My System. This will help keep Mac optimized and enhance the performance of your system.

Read More – How To Uninstall Programs On A Mac

2. Fix The File Is Locked message

If a file is locked, then you cannot move it to Bin. To unlock a file and move to Bin, follow these steps:

5. If this doesn’t work, you can head to Mac’s Terminal to unlock the file.

6. Type the following command:

chflags nouchg /path/to/file

7. file is the name of the file you want to remove.

This will unlock the file. Now you can select the file and Move it to Bin..

Read More – Advanced Uninstall Manager – Is It Miles Ahead Than Your Regular Uninstaller

3. Fix – You Don’t Have Permission to Edit the File

When moving an app to Trash, if you get the “You don’t have permission to edit this file”, follow these steps.

4. When prompted, enter your username and password.

6. This will give permission to edit the file.

7. Select the file and then drag it to the Bin.

4. Bonus Tip

If none of the above fixes have worked so far, try the Force Delete option using the Terminal command.

Note: Force deleting the file doesn’t move it to Bin – it is permanently deleted. This means you cannot restore the file. Therefore, use this method wisely. Using this step, you can also delete the files that normally won’t delete. But remember Apple protects certain files for some reasons therefore, don’t use this method to delete those files.

Force-delete is a useful technique but should be used with caution.

To force-delete a file, follow these steps.

2. When in Terminal, type the following command:

rm -f /path/to/file

3. Now select the file you want to delete and move it to Bin.

This is it, using these simple steps, you can delete files that won’t get deleted. We hope you managed to move the apps to Bin using the steps explained above.

Now, that the files are deleted, you won’t want them to sit in the Bin and eat up storage space right? The best way to avoid this is to empty trash. In addition to this, you can also remove junk files and other unwanted data that take unnecessary space.

For this, you can try using Cleanup My System. The best Mac optimization utility that helps clean junk files, identify large and old files. Also, it helps empty trash without any issues.

To use it follow these steps:

1. Download and install Cleanup My System

2. Launch the Mac cleanup tool

6. Select the files you want to remove permanently from your Mac

Alongside, you can also use other modules provided by Cleanup My System. This will help keep Mac optimized and enhance the performance of your system.

Wrapping Up

Related Topics

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About the author

Aayush Yadav

How To Delete Duplicate Photos Using Duplicate Photos Fixer

How to Delete Duplicate Photos In Windows 10

Also Read: 10 Best Duplicate Photo Finders & Removers For Windows

Learn How To Delete Duplicate Photos in Windows:

Step – 1

The duplicate photo remover lets you do this in two ways –

You can simply drag the photos or folders that you wish to be scanned and drop it in the scan list.

Step – 2

Now, to be even more precise with your selection you can choose the matching criteria present at the right-hand side of the duplicate photo cleaner. Under this section you will find options like matching level, bitmap size, time interval and GPS. Each of these subsections is accompanied by a slider. Depending on how accurate and strict you wish your results to be, you can pull the slider from low to high. It is always recommended that you choose the “similar match” in the comparison method.

Step – 3

Once satisfied with the matching criteria, you can now hit the “scan for duplicates” tab present on the bottom left of the interface. The software will then look for all the similar and duplicate images and deliver the results in a few seconds.   

 Step – 4

 This step allows you to manually or automatically delete the selected images. After the completion of the scan you can –

Manually select the images that you wish to keep or delete.

Let’s start with 24 hours free trial version of Duplicate Photo Fixer and also get 20% instant discount while upgrade to pro version!!

Checkout the list of Best Duplicate Photo Finder And Cleaner Tools For Windows And Mac.

Reasons for Choosing Duplicate Photos Fixer Pro To Delete Duplicate Photos

It goes without saying that lesser the images easier it is to identify them. This brings us to why you should have a duplicate photo finder tool in your PC –

The tool helps identification of duplicate and similar photos easy and fast.

When you remove Duplicate Photos on Windows you get a neat and sorted gallery. It makes it so much easier for you to organize and edit photos in windows as per your wishes in a streamlined fashion.

Duplicate Photos Fixer Pro is a duplicate photo cleaner that helps you get rid of excess space on your disk which can be utilized for other files and since your disk space becomes lighter, the performance of your PC improves considerably.

Next Read:

Duplicate Photos Fixer Pro vs Ashisoft Duplicate Photo Finder

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About the author

Sarang Bhargava

How To Delete All Files From Google Drive.

If you are trying to delete everything from your Google Drive account in one go but can’t seem to figure out exactly how to do it. This article will show you how to permanently delete everything you have stored on your Google Drive account. Unfortunately, there isn’t a quick easy-to-find solution that is obvious for everyone.

Related: How to fix the Google Drive sign-in loop error.

Google Drive is one of the best free storage services currently available offering a whopping 15GB of free storage space. Something that no other service can compare with. However, if you are also subscribed to a paid plan this can go all the way up to 30Gb. While this is awesome Google doesn’t offer a quick and easy way to clear all your files from your Drive account.

The good news is that there is a reasonable way to remove everything, though it does take a little time and isn’t a simple option or a tool. If you happen to have folders set up the process is straightforward as you can just delete the core folders one by one. But if you just have everything in the base Google Drive folder things are a little more complicated.

How do you delete all files from your Google Drive account? Delete everything from Google Drive.

To begin, the first thing that you will need to do is visit the Google Drive website and sign into your Google account (the one you want to delete everything from).

This will show you every single thing that you currently have stored on your Google Drive account.

Next, comes the annoying part. You are going to have to keep scrolling down the page until you reach the very bottom. Which may take a while if you have a lot of files.

Can I use this process to delete single or multiple files rather than everything?

If you just want to delete a few files you can use the exact same process, in fact, it’s usually a lot quicker. Just be aware that anything in the Bin will get automatically removed within 30 days.

Using Google Backup and Sync? Just delete the backup device and everything on it will be removed.

Delete All Odd Elements From An Array In Java

An array is a collection of similar data types (such as integers, floats, or characters) that are stored together in contiguous memory locations and can be accessed using an index or a subscript.

Arrays are commonly used to store and manipulate large amounts of data in a program. They provide a convenient way to group related data together and allow for efficient access to individual elements of the array.

Here we have given an array which contains set of elements including even as well as odd elements and as per the problem statement we have to delete all odd elements from that array of integers.

Let’s start!

To show you some instances Instance-1 Original array: [23, 12, 45, 65, 34, 23, 54, 76, 20] Array after deleting odd elements: [12, 34, 54, 76, 20] Instance-2 Original array: [-22, 45, 23, 65, -9, 26] Array after deleting odd elements: [-22, 26] Instance-3 Original array: [123, 345, 657, 342, 344] Array after deleting odd elements: [342, 344] Algorithm Algorithm-1

Step-1 − Create a new array.

Step-2 − Iterate through the input array and adds even elements to a new array.

Step-3 − It then creates a new array with the even elements and returns it.

Step-4 − This program prints out the original array and the resulting array after deleting odd elements.

Step-5 − It uses a method to delete odd elements from an array of integers in Java.

Algorithm-2

Step-1 − Create an ArrayList with elements.

Step-2 − Iterates through the input array and add even elements to an ArrayList.

Step-3 − It then creates a new arraylist with the even elements and returns it.

Step-4 − This program prints out the original array and the resulting arraylist after deleting odd elements.

Step-5 − It uses an ArrayList to delete odd elements from an array of integers in Java.

Syntax

1. The length method in Java returns the length of the given array.

Below refers to the syntax of it −

inputArray.lenght

Where, ‘inputArray’ refers to the given array.

2. size() method returns the number of elements in a collection, such as an ArrayList or a LinkedList. It is a built-in method in Java and can be used to determine the size of a collection at any given time.

Below refers to the syntax of it −

evenList.size()

Where, ‘evenList’ refers to ArrayList to store the even elements from the input array.

3. The get() method returns the element at a specified index in a collection, such as an ArrayList or a LinkedList. It is a built-in method in Java and can be used to access a specific element in a collection by its index.

Below refers to the syntax of it −

evenList.size()

Where, ‘evenList’ refers to ArrayList to store the even elements from the input array.

Multiple Approaches

We have provided the solution in different approaches.

By Using New Array

By Using ArrayList

Let’s see the program along with its output one by one.

Approach-1: By Using New Array

In this approach, array elements will be initialized in the program. Then call a user defined method by passing the array as parameter and inside method as per the algorithm-1 using a new array deletes all odd elements from that array.

Example import java.util.Arrays; public class Main { public static void main(String[] args) { int[] inputArray = {1, 2, 3, 4, 5, 6, 7, 8, 9}; int[] resultArray = delOddElmts(inputArray); System.out.println("Original array: " + Arrays.toString(inputArray)); System.out.println("Array after deleting odd elements: " + Arrays.toString(resultArray)); } public static int[] delOddElmts(int[] arr) { int[] evenArr = new int[arr.length]; int j = 0; for (int i = 0; i < arr.length; i++) { if (arr[i] % 2 == 0) { evenArr[j] = arr[i]; j++; } } int[] result = new int[j]; for (int i = 0; i < j; i++) { result[i] = evenArr[i]; } return result; } } Output Original array: [1, 2, 3, 4, 5, 6, 7, 8, 9] Array after deleting odd elements: [2, 4, 6, 8] Approach-2: By Using ArrayList

In this approach, array elements will be initialized in the program. Then call a user defined method by passing the array as parameter and inside method as per the algorithm-2, by using the ArrayList delete all odd elements from that array.

Example import java.util.ArrayList; import java.util.Arrays; import java.util.List; public class Main { public static void main(String[] args) { int[] inputArray = {23,12,45,65,34,23,54,76,20}; int[] resultArray = delOddElmts(inputArray); System.out.println("Original array: " + Arrays.toString(inputArray)); System.out.println("Array after deleting odd elements: " + Arrays.toString(resultArray)); } public static int[] delOddElmts(int[] arr) { for (int i = 0; i < arr.length; i++) { if (arr[i] % 2 == 0) { evenList.add(arr[i]); } } int[] result = new int[evenList.size()]; for (int i = 0; i < evenList.size(); i++) { result[i] = evenList.get(i); } return result; } } Output Original array: [23, 12, 45, 65, 34, 23, 54, 76, 20] Array after deleting odd elements: [12, 34, 54, 76, 20]

In this article, we explored different approaches to delete all odd elements from an array by using Java programming language.

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