Pandas Pt 1 - Cont'd (UCSD)

Question 1

basic descriptive statistics functions for all columns on a datframe df

Answer 1

df.describe(), df.corr(), df.mean(), df.median(), df.mode(), df. min(), df.max() , df.std()

Question 2

use axis to get statistical values for the columns or the rows (mean as example)

Answer 2

df.mean(axis = 1) ## 0 index, 1 columns

Question 3

check if any element in a dataframe or series is `non-zero or non-empty (but mostly useful w/ a boolean column)

Answer 3

df.any()

Question 4

check if ALL element in a dataframe or series is `non-zero or non-empty (but mostly useful w/ a boolean column)

Answer 4

df.all()

Question 5

use describe on a column of df_var called ‘ratings’

Answer 5

df[‘ratings’].describe()

Question 6

Create a series with Boolean values if the rating column from ratings df is > 5, then use any() to test for true on the series

Answer 6

filter_1 = ratings[‘rating’] > 5 ## not sure if this is a series, or 1 col df
filter_1.any()

Question 7

Get the mean value from ‘rating’ col for all rows that have movieId of 1, from dataframe ratings

Answer 7

ratings[‘rating’][ratings.movieId==1].mean()