Tarun Ruchandani rtarun

## useful_pandas_snippets.py

# List unique values in a DataFrame column
pd.unique(df.column_name.ravel())

# Convert Series datatype to numeric, getting rid of any non-numeric values
df['col'] = df['col'].astype(str).convert_objects(convert_numeric=True)

# Grab DataFrame rows where column has certain values
valuelist = ['value1', 'value2', 'value3']
df = df[df.column.isin(valuelist)]

## .block
license: gpl-3.0

## .block
license: gpl-3.0
height: 600

## System Design.md

      
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                rtarun
                / System Design.md
            
            
              Created
              January 28, 2019 22:11
                — forked from vasanthk/System Design.md
            
              
                System Design Cheatsheet
              
          
    System Design Cheatsheet


Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps


Clarify and agree on the scope of the system


User cases (description of sequences of events that, taken together, lead to a system doing something useful)

Who is going to use it?
How are they going to use it?

	# List unique values in a DataFrame column
	pd.unique(df.column_name.ravel())

	# Convert Series datatype to numeric, getting rid of any non-numeric values
	df['col'] = df['col'].astype(str).convert_objects(convert_numeric=True)

	# Grab DataFrame rows where column has certain values
	valuelist = ['value1', 'value2', 'value3']
	df = df[df.column.isin(valuelist)]