describe

Print summary statistics of the columns in a dataset to standard output (stdout).

The summary includes the following information:

count: the number of non-empty data values observed for the column

For categorical columns:

unique: the number of unique values observed for the column
top: the most frequently observed value
freq: the frequency (count) of the most frequently observed value

For numerical columns:

mean: the mean (average)
std: the standard deviation
min: the minimum observed value
25%: the 25th percentile
50%: the 50th percentile
75%: the 75th percentile
max: the maximum observed value

Usage

gurita describe [-h] [-c [COLUMN ...]]

Arguments

Argument	Description	Reference
`-h` `--help`	display help for this command	help
`-c [COLUMN ...]` `--col [COLUMN ...]`	select columns to describe (default is all columns)	columns

Simple example

Describe all the columns in the titanic.csv file:

gurita describe < titanic.csv

The output for the above command is as follows:

          survived      pclass   sex         age       sibsp       parch  \
count   891.000000  891.000000   891  714.000000  891.000000  891.000000   
unique         NaN         NaN     2         NaN         NaN         NaN   
top            NaN         NaN  male         NaN         NaN         NaN   
freq           NaN         NaN   577         NaN         NaN         NaN   
mean      0.383838    2.308642   NaN   29.699118    0.523008    0.381594   
std       0.486592    0.836071   NaN   14.526497    1.102743    0.806057   
min       0.000000    1.000000   NaN    0.420000    0.000000    0.000000   
25%       0.000000    2.000000   NaN   20.125000    0.000000    0.000000   
50%       0.000000    3.000000   NaN   28.000000    0.000000    0.000000   
75%       1.000000    3.000000   NaN   38.000000    1.000000    0.000000   
max       1.000000    3.000000   NaN   80.000000    8.000000    6.000000   

              fare embarked  class  who adult_male deck  embark_town alive  \
count   891.000000      889    891  891        891  203          889   891   
unique         NaN        3      3    3          2    7            3     2   
top            NaN        S  Third  man       True    C  Southampton    no   
freq           NaN      644    491  537        537   59          644   549   
mean     32.204208      NaN    NaN  NaN        NaN  NaN          NaN   NaN   
std      49.693429      NaN    NaN  NaN        NaN  NaN          NaN   NaN   
min       0.000000      NaN    NaN  NaN        NaN  NaN          NaN   NaN   
25%       7.910400      NaN    NaN  NaN        NaN  NaN          NaN   NaN   
50%      14.454200      NaN    NaN  NaN        NaN  NaN          NaN   NaN   
75%      31.000000      NaN    NaN  NaN        NaN  NaN          NaN   NaN   
max     512.329200      NaN    NaN  NaN        NaN  NaN          NaN   NaN   

       alone  
count    891  
unique     2  
top     True  
freq     537  
mean     NaN  
std      NaN  
min      NaN  
25%      NaN  
50%      NaN  
75%      NaN  
max      NaN  

Getting help

The full set of command line arguments for describe can be obtained with the -h or --help arguments:

gurita describe -h

Select specific columns to describe

-c [COLUMN ...], --col [COLUMN ...]

By default describe prints information about all columns in a dataset.

Alternatively, a subset of the columns can be selected using the -c/--col argument.

As an example, The following commmand only shows summary information for the age and class columns in the file titanic.csv:

gurita describe --col age class < titanic.csv

The output of the above command is as follows:

               age  class
count   714.000000    891
unique         NaN      3
top            NaN  Third
freq           NaN    491
mean     29.699118    NaN
std      14.526497    NaN
min       0.420000    NaN
25%      20.125000    NaN
50%      28.000000    NaN
75%      38.000000    NaN
max      80.000000    NaN

Usage in a command chain

When used in a command chain the describe command passes on its input data to the rest of the chain unchanged.

For example, the following command shows describe followed by a box plot:

gurita describe + box -x sex -y age < titanic.csv

This command will first run describe to display a summary of the data on the output, and then it will run box to generate a plot on the same input data.

Because describe just passes the data along from left to right the box command receives the same data as its input that was read from the file.

It is also worth noting that describe can be used after other transformations have been applied to the data. For example, the data can be filtered first, and then the result of filtering can be fed into describe:

gurita filter 'age >= 30' + describe < titanic.csv