Uniqueness Constraints

Question 1

What is a list that contains duplicates when there are at least two identical elements in the list?

Answer 1

duplicated values

Question 2

How do you find duplicated values?

Answer 2

dataframe. duplicated()
1. subset: list of column names to check for duplication
2. keep: weather to keep first (‘first’), last (‘last’) name or all (False) duplicate values

duplicates= dataframe.duplicated(subset = column, keep= False)

3.dataframe[duplicates]. sort_values(by= first name)

Question 3

What’s a built-in function that is available in a standard installation of Python. with no additional arguments or parameters, is ordering the values in numbers in ascending order, meaning smallest to largest?

Answer 3

.sort_values

Question 4

How do you drop a duplicate?

Answer 4

dataframe. drop_duplicated()
1. subset: list of column names to check for duplication
2. keep: weather to keep first (‘first’), last (‘last’) name or all (False) duplicate values

duplicates= dataframe.duplicated(subset = column, keep= False)

3. inpalce: drop rows directly into the Dataframe without creating new object (True)
   dataframe. drop_duplicates(inplace= True)
4. dataframe[duplicates]. sort_values(by= first name)

Question 5

What operation involves some combination of splitting the object, applying a function, and combining the results. This can be used to group large amounts of data and compute operations on these groups.

Answer 5

.groupby()

dataframe.groupby(by= colmunn)

Question 6

What function is used to apply some aggregation across one or more column. Aggregate using callable, string, dict, or list of string/callables. Most frequently used aggregations are:

sum: Return the sum of the values for the requested axis
min: Return the minimum of the values for the requested axis
max: Return the maximum of the values for the requested axis

Answer 6

.agg()