snake pit

comprehension — DataFrame — generator

A

.add #adds an element to a set, if the element does not exist already in the set

.agg() #aggregates values in pandas

and #logical and

.any() #checks existence in data frames

.append() #adds to a list

.apply() #applies command on data frame value in pandas

array #is a datatype in numpy

.array() #creates an array in the numpy package

.bit_length() # 

bool #is a datatype

  bool() #makes a Boolean True or False from many objects

break #breaks loops

C

.capitalize() #makes upper case of the first letter

.chdir() #changes the directory in the os modul

chunksize #set a date portion size to load chunks in pandas' .import_csv

.clf() #erases output charts in pyplot

close() #closes a file

.columns #gives header names of data frame in pandas

.column_stack() #stacks values in numypy

Counter() #used in the collections module

.concat() #cancatenates in pandas

.conjugate() #

.cos #gives cosinus in the math package

.corrcoef() #correlation in numpy

.count() #counts elements in a list, or count of a specific element

.countplot() #creates a column chart in seaborn

.cummax() #cumulative max in pandas

.cummin() #cumulative min in pandas

.cumprod() #cumulative viz. running product in pandas

.cumsum() #cumulative viz. running sum in pandas

D

.DataFrame() #creates a table in the panda package

.date #creates a yyyy-mm-dd date in the datetime modul

def #defines a function

defaultdict() #special dictionary in the collections module

del #deletes

  del my_list[n] #delete the n-th element from the list my_list

.describe() #gives overview for numerical values of a dataf rame

dict() #creates an empty dictionary

.difference #shows differnce between a set and a target set

.discard() #removes elements from a set

.drop_duplicates #deletes duplicates in a dataf rame in pandas

.dropna() #deletes rows with missing data in a data frame

.dt #datetime object viz. date column in a data frame

  .dt.day #accesses the year of a date column in a data frame

  .dt.year #accesses the year of a date column in a data frame

  .dt.month #accesses the year of a date column in a data frame

E

elif #else-if statement in a condition

else #else statement in conditions

.endswith("x") #tells if a string ends with "x" 

.environ #give the local environment in the os modul

enumarte() #creates an enumaration for an iterable

except #defines code to run when an error occurs, and subsequent code is executed

.extend() #combines lists

F

f #starts a formated string literal 

False #logical false

.fillna() replaces null values in a pandas' data frame

filter() #filters

float #is a datatype

for #start a for-loop

  [element if element == condition else 0 for element in list]

  [element for element in list if element == condition]  

format() #formats with a given patern

from package_anme import function #imports only a function from a package or modul

  from package_anme import func1, func2 #imports only functions func1 and func2 from a package or modul

.get() #gets a value from a dictionary avoiding error messages

.getcwd() #gets the current working directory in the os modul

.grid() #add grid lines in pyplot

.groupyby() #aggregates on groups in pandas

.head() #gives the first few rows of a data frame viz. table in the panda package

help() #shows documentation

.hist() #plots a histogram in pyplot

I

if #starts if condition

  [element if element == condition else 0 for element in list]

  [element for element in list if element == condition]  

.iloc #accesses data frames by their indexes

import #imports a package, or a modul

  import package_anme as my_name  #imports a package with an assigned name

in #logical check if a value exist in a variable or data structure

.index #gives row numbers or labels of data frame

.index() #gives e.g. the position in an iteration, or  creates name labels in data frame

index_col #sets the index for a data frame in .read_csv()

.info() #gives column names of data frames in pandas

int #is a datatype

  int() #makes an integer

.intersection() #intersection of sets

is #logical is operation

.isin # filters values in a data frame in pandas

.isna() #scans for missing values

  .isna().any() #scans for missing values by field

.items #gives the keys and values of a dictionary as tuples in a list

iter() #creates a iterator for iterables

.iterrows() #allows loops in data frames

.join() #joins an iterable to a string

.keys #gives the keys of a dictionary, not the values

L

lambda #creates an anonymos function

.legend() #creates label legend in matplotlib

len() #give the length of a string, or the number of elements in a collection

list #is a collection

  list() #creates a list

.loc #accesses data frames by their names

.logical_and() #and in numpy for arrays

.logical_not() #notin numpy for arrays

.logical_or() #or in numpy for arrays

.lower() #creates lower case for a string#

M

map() #applies a function to an iterable i.e. sequence

max() #gives the maximal value

.max() #gives the max in pandas

.mean() #calculates the mean i.e. arithmetic average in numpy, pandas etc.

.median() #calculates the median in numpy

min() #gives the minimal value

.min() #gives the min in pandas

.most_common() #show top values in a collections module

.mode() #gives the mode in pandas

namedtuple() #special tuple variant in the collections module

.nditer #iterates over a numpy array

next() #produces next value, e.g. in iterable objects

NaN #null value Not an Nmber

None #no value

not #logical not

  not in #checks if a value does not exist in a variable or data structure

open() #opens a file

or #logical or

P

pandas #stands for panel data

.pi #gives π in the math package

pip #stands for package installer for python

.pivot_table() #creates a pivot table in pandas

.plot() #plots charts in pandas, and plots a line chart in pyplot

.pop() #deletes the last item from the list

  .pop(n) #deletes the last item at position n from the list etc.

  .pop("name") #detes the item "name" from the list etc.

pow() #alculates with the power

print() #prints an output on screen

PyPI #stands for python package index

R

raise #raises an exception viz. error message and stop code excution

.random() #creates random values in numpy

  .random.rand() #creates a random number in numpy

  .random.randint() #creates a random integer in numpy

  .random.seed(n) #sets seed n for random generator

range() #creates a sequence of numbers

  range(n,m) #n is inclusive, m is exclusive

.readline() #reads a line from a file object

.read_csv() #reads a csv into a data frame viz. table in the panda package

.relplot() #creates a relational plot in seaborn

.remove() #removes from a list

.replace() #replaces a substring

.reset_index() #resets a set index into a column in a pandas' data frame

return #returns a value from inside a function

.reverse() #reverses a list

round() #rounds a number

S

.safefig() #saves a chart in matplotlib

.scatter() #plots a scatter plot in pyplot

.scatterplt() #plots a scatter plot in seaborn

.set_size_inches([n,m]) #set figure size in inches in matplotlib

.shape #gives the number of rows and columns of a data frame in pandas

.show() #shows a chart in pyplot

set() #can cast a list to a set

.set_index() #turn a column into the index in a pandas' data frame

.set_palette() #sets palette in seaborn

.set_style() #sets style in seaborn

.set_title() #sets chart title in matplotlib and seaborn

.set_titels() #sets titels for subplots in seaborn

.set_xlabel() #names horizontal axis in matplotlib

.set_ylabel() #names the vertical axis in matplotlib

.std() #standard deviation in numpy and pandas

sort() #sorts values

  .sort() #sorts values faster in numpy

.sort_index() #sorts on the index of a dataframe in pandas

.sort_values("header") #sorts column "header" of a dataframe in pandas

sorted() #sorts a set and returns a list

.split() #splits a string

  .split("x") #splits at substring "x"

.startswith("x") #tells if a string starts with "x"

str #is a datatype

  str() #creates a string

.style #a style in matplotlip

  .style.use() #set a style in matplotlip

sum() #sums values

  .sum() #sums values faster in numpy, pandas etc.

.suptitle() #sets a title for FaceGrit objects in seaborn

T

.text() #adds text inside the chart in pyplot

.tick_params() #settings for axis ticks in matplotlib

.title() #makes a title case for strings, or adds title to chart in pyplot

.to_csv() #creates a csv file from a data frame in pandas

.transpose() #transposes a numpy array

True #logical true

try #starts a try block for testing code in error handling

tuple() #converts into a tuple

.twinx() #twin copy of x axis in matplotlib

type() #gives the data type like int, float, bool, or str

.union() #union of sets

.unique() #makes a list unique

update() #add to dictionary, set etc.

  .update({"my_key": value}) #updates or add to a dictionary

.upper() #makes all letters upper case

V

.values #gives the values of a dictionary, not the keys, and for a data frame

.value_counts() #counts values in a data frame

.var() #gives the variance in pandas

while #starts a while-loop

with open #opens, and closes a file

.xlabel() #labels horizontal axis in pyplot

.xscale() #set the scale of the horizontal axis in pyplot

.xticks() #change ticks on the horizontal axis in pyplots

yield #generator functions do not return, but they yield values back

.ylable() #labels vertical axis in pyplot

.yticks() #change ticks on the vertical axis in pyplots

zip() #combines interables

# #indicates a comment

? #shows documentation

= #calculation sign, and assigning values to variable, but Boolean values need ==

== #checks equality as True and False, is used to compare strings and values

!= # logical not equal

+ #sums numbers, or concatenates strings or lists

* #multiplies numbers, strings etc.

** #is the power of a number, or creates an arbitrary keyword argument i.e. unlimited input quantity of arguments

= #assigns a value

" #starts and ends a string

' #starts and ends a string

""" #makes a multi line string

% #modulo operator viz. rest of division

/ #division

// #floor division where the output is the floored integer

() #creates tuples, sets, generator expressions etc.

[] #creates a list i.e. collection etc.

  [ … , … , … ] #is a collection of elements

  [n] #indexes the n-th element in the list with first n = 0

  [-n] #indexes the n-th element in the list from the back with last n = -1

  [ … : … ] #slices as list

  [:] #creates an explicit copy a list i.e. it handels independedly

  [ … , … ] #accesses an array by row and column index

  [[ … ]] #reads a data frame column into a new data frame object

{} #creates a dictiobary or set i.e. collections, inserts objects into f-strings

  { "key": value , … } #is a dictionary

  { … , … } #is a set

> #greater

>= #greater or equal

< #less

<= #less or or equal

: #indicates a task to perform, and placeholder in collections

__ #dunder, double under

functions

https://docs.python.org/3/library/functions.html