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Top Questions People Ask About Pandas, NumPy, Matplotlib & Scikit-learn — Answered!

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 Whether you're a beginner or brushing up on your skills, these are the real-world questions Python learners ask most about key libraries in data science. Let’s dive in! 🐍 🐼 Pandas: Data Manipulation Made Easy 1. How do I handle missing data in a DataFrame? df.fillna( 0 ) # Replace NaNs with 0 df.dropna() # Remove rows with NaNs df.isna(). sum () # Count missing values per column 2. How can I merge or join two DataFrames? pd.merge(df1, df2, on= 'id' , how= 'inner' ) # inner, left, right, outer 3. What is the difference between loc[] and iloc[] ? loc[] uses labels (e.g., column names) iloc[] uses integer positions df.loc[ 0 , 'name' ] # label-based df.iloc[ 0 , 1 ] # index-based 4. How do I group data and perform aggregation? df.groupby( 'category' )[ 'sales' ]. sum () 5. How can I convert a column to datetime format? df[ 'date' ] = pd.to_datetime(df[ 'date' ]) ...
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How to Use Help Command in HDFS

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Sometimes as a Hadoop developer it is difficult to remember all the Hadoop commands. The HELP command useful to know the correct syntax.

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How to List all HDFS Commands

hadoop
hadoop fs   ==> Enter

This will list all Hadoop commands.

Help Command in HDFS

Hadoop commands are the flavor of UNIX. If you want to see each Command description, you can go for Hadoop help command. You can use the below command for help.

hadoop fs -hlep ls 

Deleting a File in Hadoop HDFS

The below command helps   how to delete a file from Hadop cluster.

hadoop fs -rm exmaple.txt

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