Appendix A — Keyword and Function Reference

A.1 Built-in Keywords

The following table provide a complete list of the built-in keywords in Python. An online version with clickable definitions is available here.

Table A.1: The built-in keywords in Python and what they do

Keyword	Description
`and`	A logical operator
`as`	To create an alias
`assert`	For debugging
`break`	To break out of a loop
`class`	To define a class
`continue`	To continue to the next iteration of a loop
`def`	To define a function
`del`	To delete an object
`elif`	Used in conditional statements, same as else if
`else`	Used in conditional statements
`except`	Used with exceptions, what to do when an exception occurs
`finally`	Used with exceptions, will be executed no matter what occurs
`for`	To create a for loop
`from`	To import specific parts of a module
`global`	To declare a global variable
`if`	To make a conditional statement
`import`	To import a module
`in`	To check if a value is present in a list, tuple, etc.
`is`	To test if two variables are equal
`lambda`	To create an anonymous function
`nonlocal`	To declare a non-local variable
`not`	A logical operator
`or`	A logical operator
`pass`	A null statement, a statement that will do nothing
`raise`	To raise an exception
`return`	To exit a function and return a value
`try`	To make a try…except statement
`while`	To create a while loop
`with`	Used to simplify exception handling
`yield`	To return a list of values from a generator

A.2 Built-in Functions

The following table provides a comprehensive list of the built-in function included in Python. An online version of this list with clickable definitions to the functions is available here.

Table A.2: The built-in functions in Python and what they do

Function	Description
`abs()`	Returns the absolute value of a number
`all()`	Returns `True` if all items in an iterable object are `True`
`any()`	Returns `True` if any item in an iterable object is `True`
`ascii()`	Returns a readable version of an object
`bin()`	Returns the binary version of a number
`bool()`	Returns the boolean value of the specified object
`bytearray()`	Returns an array of bytes
`bytes()`	Returns a bytes object
`callable()`	Returns `True` if the specified object is callable, otherwise `False`
`chr()`	Returns a character from the specified Unicode code.
`classmethod()`	Converts a method into a class method
`compile()`	Returns the specified source as an object, ready to be executed
`complex()`	Returns a complex number
`delattr()`	Deletes the specified attribute (property or method) from the specified object
`dict()`	Returns a dictionary (`dict`)
`dir()`	Returns a `list` of the specified object’s properties and methods
`divmod()`	Returns the quotient and the remainder when argument1 is divided by argument2
`enumerate()`	Takes a collection (e.g. a `tuple`) and returns it as an enumerate object
`eval()`	Evaluates and executes an expression
`exec()`	Executes the specified code (or object)
`filter()`	Use a filter function to exclude items in an iterable object
`float()`	Returns a floating point number
`format()`	Formats a specified value
`frozenset()`	Returns a frozenset object
`getattr()`	Returns the value of the specified attribute (property or method)
`globals()`	Returns the current global symbol table as a dictionary
`hasattr()`	Returns `True` if the specified object has the specified attribute
`hash()`	Returns the hash value of a specified object
`help()`	Executes the built-in help system
`hex()`	Converts a number into a hexadecimal value
`id()`	Returns the id of an object
`input()`	Allowing user input
`int()`	Returns an integer number
`isinstance()`	Returns `True` if a specified object is an instance of a specified object
`issubclass()`	Returns `True` if a specified class is a subclass of a specified object
`iter()`	Returns an iterator object
`len()`	Returns the length of an object
`list()`	Returns a `list`
`locals()`	Returns an updated dictionary of the current local symbol table
`map()`	Returns the specified iterator with the specified function applied to each item
`max()`	Returns the largest item in an iterable
`memoryview()`	Returns a memory view object
`min()`	Returns the smallest item in an iterable
`next()`	Returns the next item in an iterable
`object()`	Returns a new object
`oct()`	Converts a number into an octal
`open()`	Opens a file and returns a file object
`ord()`	Convert an integer representing the Unicode of the specified character
`pow()`	Returns the value of x to the power of y
`print()`	Prints to the standard output device
`property()`	Gets, sets, deletes a property
`range()`	Returns a sequence of numbers, starting from 0 and increments by 1 (by default)
`repr()`	Returns a readable version of an object
`reversed()`	Returns a reversed iterator
`round()`	Rounds a numbers
`set()`	Returns a new `set` object
`setattr()`	Sets an attribute (property/method) of an object
`slice()`	Returns a slice object
`sorted()`	Returns a sorted list
`staticmethod()`	Converts a method into a static method
`str()`	Returns a string object
`sum()`	Sums the items of an iterator
`super()`	Returns an object that represents the parent class
`tuple()`	Returns a `tuple`
`type()`	Returns the type of an object
`vars()`	Returns the dict property of an object
`zip()`	Returns an iterator, from two or more iterators

A.3 `list` Methods

A full list of methods with clickable definitions can be found here.

Table A.3: List of methods on a list object

Method	Description
`append`	Adds a new item to the end itself
`clear`	Deletes all items from itself
`copy`	Returns a copy of itself
`count`	Returns the number of times the given value occurs itself
`extend`	Joins another list to the end of itself
`index`	Retuns the first location of the given value
`insert`	Writes the given value to the given location
`pop`	Removes the item at the given address and returns it
`remove`	Removes the first occurance of the given value
`reverse`	Reverse the order of itself
`sort`	Sorts the values in place

A.4 `dict` Methods

A detailed tutorial on using dictionaries (dicts) can be found on the RealPython website. A full list of methods with clickable definitions can be found here.

Table A.4: List of methods on a dict object

Method	Description
`clear`	Removes all the elements from the dictionary
`copy`	Returns a copy of the dictionary
`fromkeys`	Returns a dictionary with the specified keys and value
`get`	Returns the value of the specified key
`items`	Returns a list containing a tuple for each key value pair
`keys`	Returns a list containing the dictionary’s keys
`pop`	Removes the element with the specified key
`popitem`	Removes the last inserted key-value pair
`setdefault`	Returns the value of the specified key. If the key does not exist: insert the key, with the specified value
`update`	Updates the dictionary with the specified key-value pairs
`values`	Returns a list of all the values in the dictionary

A.5 `set` Methods

The following methods are available on set objects. A detailed tutorial of using sets can be found here.

Table A.5: List of methods on a set object

Method	Description
`add()`	Adds an element to the set
`clear()`	Removes all the elements from the set
`copy()`	Returns a copy of the set
`difference()`	Returns a set containing the difference between two or more sets
`difference_update()`	Removes the items in this set that are also included in another, specified set
`discard()`	Remove the specified item
`intersection()`	Returns a set, that is the intersection of two other sets
`intersection_update()`	Removes the items in this set that are not present in other, specified set(s)
`isdisjoint()`	Returns whether two sets have a intersection or not
`issubset()`	Returns whether another set contains this set or not
`issuperset()`	Returns whether this set contains another set or not
`pop()`	Removes an element from the set
`remove()`	Removes the specified element
`symmetric_difference()`	Returns a set with the symmetric differences of two sets
`symmetric_difference_update()`	Inserts the symmetric differences from this set and another
`union()`	Return a set containing the union of sets
`update()`	Update the set with the union of this set and others

A.6 `str` Methods

Table A.6: List of methods attached to a str object

Method	Description
`capitalize()`	Converts the first character to upper case
`casefold()`	Converts string into lower case
`center()`	Returns a centered string
`count()`	Returns the number of times a specified value occurs in a string
`encode()`	Returns an encoded version of the string
`endswith()`	Returns `True` if the string ends with the specified value
`expandtabs()`	Sets the tab size of the string
`find()`	Searches the string for a specified value and returns the position of where it was found
`format()`	Formats specified values in a string
`format_map()`	Formats specified values in a string
`index()`	Searches the string for a specified value and returns the position of where it was found
`isalnum()`	Returns `True` if all characters in the string are alphanumeric
`isalpha()`	Returns `True` if all characters in the string are in the alphabet
`isascii()`	Returns `True` if all characters in the string are ascii characters
`isdecimal()`	Returns `True` if all characters in the string are decimals
`isdigit()`	Returns `True` if all characters in the string are digits
`isidentifier()`	Returns `True` if the string is an identifier
`islower()`	Returns `True` if all characters in the string are lower case
`isnumeric()`	Returns `True` if all characters in the string are numeric
`isprintable()`	Returns `True` if all characters in the string are printable
`isspace()`	Returns `True` if all characters in the string are whitespaces
`istitle()`	Returns `True` if the string follows the rules of a title
`isupper()`	Returns `True` if all characters in the string are upper case
`join()`	Converts the elements of an iterable into a string
`ljust()`	Returns a left justified version of the string
`lower()`	Converts a string into lower case
`lstrip()`	Returns a left trim version of the string
`maketrans()`	Returns a translation table to be used in translations
`partition()`	Returns a tuple where the string is parted into three parts
`replace()`	Returns a string where a specified value is replaced with a specified value
`rfind()`	Searches the string for a specified value and returns the last position of where it was found
`rindex()`	Searches the string for a specified value and returns the last position of where it was found
`rjust()`	Returns a right justified version of the string
`rpartition()`	Returns a `tuple` where the string is parted into three parts
`rsplit()`	Splits the string at the specified separator, and returns a `list`
`rstrip()`	Returns a right trim version of the string
`split()`	Splits the string at the specified separator, and returns a `list`
`splitlines()`	Splits the string at line breaks and returns a `list`
`startswith()`	Returns `True` if the string starts with the specified value
`strip()`	Returns a trimmed version of the string
`swapcase()`	Swaps cases, lower case becomes upper case and vice versa
`title()`	Converts the first character of each word to upper case
`translate()`	Returns a translated string
`upper()`	Converts a string into upper case
`zfill()`	Fills the string with a specified number of `0` values at the beginning

A.7 `file` Methods

The following list gives the various methods which are attached to a file object. An online version of this list with clickable definitions to the functions is available here.

Table A.7: List of methods attached to a file object

Method	Description
`close()`	Closes the file
`detach()`	Returns the separated raw stream from the buffer
`fileno()`	Returns a number that represents the stream, from the operating system’s perspective
`flush()`	Flushes the internal buffer
`isatty()`	Returns whether the file stream is interactive or not
`read()`	Returns the file content
`readable()`	Returns whether the file stream can be read or not
`readline()`	Returns one line from the file
`readlines()`	Returns a list of lines from the file
`seek()`	Change the file position
`seekable()`	Returns whether the file allows us to change the file position
`tell()`	Returns the current file position
`truncate()`	Resizes the file to a specified size
`writable()`	Returns whether the file can be written to or not
`write()`	Writes the specified string to the file
`writelines()`	Writes a list of strings to the file

A.8 `DataFrame` Methods

For a full interactive list see the W3 Schools Page

Table A.8

Method	Description
`abs`	Return a DataFrame with the absolute value of each value
`add`	Adds the values of a DataFrame with the specified value(s)
`add_prefix`	Prefix all labels
`add_suffix`	Suffix all labels
`agg`	Apply a function or a function name to one of the axis of the DataFrame
`aggregate`	Apply a function or a function name to one of the axis of the DataFrame
`align`	Aligns two DataFrames with a specified join method
`all`	Return True if all values in the DataFrame are True, otherwise False
`any`	Returns True if any of the values in the DataFrame are True, otherwise False
`append`	Append new columns
`applymap`	Execute a function for each element in the DataFrame
`apply`	Apply a function to one of the axis of the DataFrame
`assign`	Assign new columns
`astype`	Convert the DataFrame into a specified dtype
`at`	Get or set the value of the item with the specified label
`axes`	Returns the labels of the rows and the columns of the DataFrame
`bfill`	Replaces NULL values with the value from the next row
`bool`	Returns the Boolean value of the DataFrame
`columns`	Returns the column labels of the DataFrame
`combine`	Compare the values in two DataFrames, and let a function decide which values to keep
`combine_first`	Compare two DataFrames, and if the first DataFrame has a NULL value, it will be filled with the respective value from the second DataFrame
`compare`	Compare two DataFrames and return the differences
`convert_dtypes`	Converts the columns in the DataFrame into new dtypes
`corr`	Find the correlation (relationship) between each column
`count`	Returns the number of not empty cells for each column/row
`cov`	Find the covariance of the columns
`copy`	Returns a copy of the DataFrame
`cummax`	Calculate the cumulative maximum values of the DataFrame
`cummin`	Calculate the cumulative minmum values of the DataFrame
`cumprod`	Calculate the cumulative product over the DataFrame
`cumsum`	Calculate the cumulative sum over the DataFrame
`describe`	Returns a description summary for each column in the DataFrame
`diff`	Calculate the difference between a value and the value of the same column in the previous row
`div`	Divides the values of a DataFrame with the specified value(s)
`dot`	Multiplies the values of a DataFrame with values from another array-like object, and add the result
`drop`	Drops the specified rows/columns from the DataFrame
`drop_duplicates`	Drops duplicate values from the DataFrame
`droplevel`	Drops the specified index/column(s)
`dropna`	Drops all rows that contains NULL values
`dtypes`	Returns the dtypes of the columns of the DataFrame
`duplicated`	Returns True for duplicated rows, otherwise False
`empty`	Returns True if the DataFrame is empty, otherwise False
`eq`	Returns True for values that are equal to the specified value(s), otherwise False
`equals`	Returns True if two DataFrames are equal, otherwise False
`eval`	Evaluate a specified string
`explode`	Converts each element into a row
`ffill`	Replaces NULL values with the value from the previous row
`fillna`	Replaces NULL values with the specified value
`filter`	Filter the DataFrame according to the specified filter
`first`	Returns the first rows of a specified date selection
`floordiv`	Divides the values of a DataFrame with the specified value(s), and floor the values
`ge`	Returns True for values greater than, or equal to the specified value(s), otherwise False
`get`	Returns the item of the specified key
`groupby`	Groups the rows/columns into specified groups
`gt`	Returns True for values greater than the specified value(s), otherwise False
`head`	Returns the header row and the first 5 rows, or the specified number of rows
`iat`	Get or set the value of the item in the specified position
`idxmax`	Returns the label of the max value in the specified axis
`idxmin`	Returns the label of the min value in the specified axis
`iloc`	Get or set the values of a group of elements in the specified positions
`index`	Returns the row labels of the DataFrame
`infer_objects`	Change the dtype of the columns in the DataFrame
`info`	Prints information about the DataFrame
`insert`	Insert a column in the DataFrame
`interpolate`	Replaces not-a-number values with the interpolated method
`isin`	Returns True if each elements in the DataFrame is in the specified value
`isna`	Finds not-a-number values
`isnull`	Finds NULL values
`items`	Iterate over the columns of the DataFrame
`iteritems`	Iterate over the columns of the DataFrame
`iterrows`	Iterate over the rows of the DataFrame
`itertuples`	Iterate over the rows as named tuples
`join`	Join columns of another DataFrame
`last`	Returns the last rows of a specified date selection
`le`	Returns True for values less than, or equal to the specified value(s), otherwise False
`loc`	Get or set the value of a group of elements specified using their labels
`lt`	Returns True for values less than the specified value(s), otherwise False
`keys`	Returns the keys of the info axis
`kurtosis`	Returns the kurtosis of the values in the specified axis
`mask`	Replace all values where the specified condition is True
`max`	Return the max of the values in the specified axis
`mean`	Return the mean of the values in the specified axis
`median`	Return the median of the values in the specified axis
`melt`	Reshape the DataFrame from a wide table to a long table
`memory_usage`	Returns the memory usage of each column
`merge`	Merge DataFrame objects
`min`	Returns the min of the values in the specified axis
`mod`	Modules (find the remainder) of the values of a DataFrame
`mode`	Returns the mode of the values in the specified axis
`mul`	Multiplies the values of a DataFrame with the specified value(s)
`ndim`	Returns the number of dimensions of the DataFrame
`ne`	Returns True for values that are not equal to the specified value(s), otherwise False
`nlargest`	Sort the DataFrame by the specified columns, descending, and return the specified number of rows
`notna`	Finds values that are not not-a-number
`notnull`	Finds values that are not NULL
`nsmallest`	Sort the DataFrame by the specified columns, ascending, and return the specified number of rows
`nunique`	Returns the number of unique values in the specified axis
`pct_change`	Returns the percentage change between the previous and the current value
`pipe`	Apply a function to the DataFrame
`pivot`	Re-shape the DataFrame
`pivot_table`	Create a spreadsheet pivot table as a DataFrame
`pop`	Removes an element from the DataFrame
`pow`	Raise the values of one DataFrame to the values of another DataFrame
`prod`	Returns the product of all values in the specified axis
`product`	Returns the product of the values in the specified axis
`quantile`	Returns the values at the specified quantile of the specified axis
`query`	Query the DataFrame
`radd`	Reverse-adds the values of one DataFrame with the values of another DataFrame
`rdiv`	Reverse-divides the values of one DataFrame with the values of another DataFrame
`reindex`	Change the labels of the DataFrame
`rename`	Change the labels of the axes
`rename_axis`	Change the name of the axis
`reorder_levels`	Re-order the index levels
`replace`	Replace the specified values
`reset_index`	Reset the index
`rfloordiv`	Reverse-divides the values of one DataFrame with the values of another DataFrame
`rmod`	Reverse-modules the values of one DataFrame to the values of another DataFrame
`rmul`	Reverse-multiplies the values of one DataFrame with the values of another DataFrame
`round`	Returns a DataFrame with all values rounded into the specified format
`rpow`	Reverse-raises the values of one DataFrame up to the values of another DataFrame
`rsub`	Reverse-subtracts the values of one DataFrame to the values of another DataFrame
`rtruediv`	Reverse-divides the values of one DataFrame with the values of another DataFrame
`sample`	Returns a random selection elements
`sem`	Returns the standard error of the mean in the specified axis
`select_dtypes`	Returns a DataFrame with columns of selected data types
`shape`	Returns the number of rows and columns of the DataFrame
`set_axis`	Sets the index of the specified axis
`set_flags`	Returns a new DataFrame with the specified flags
`set_index`	Set the Index of the DataFrame
`size`	Returns the number of elements in the DataFrame
`skew`	Returns the skew of the values in the specified axis
`sort_index`	Sorts the DataFrame according to the labels
`sort_values`	Sorts the DataFrame according to the values
`squeeze`	Converts a single column DataFrame into a Series
`stack`	Reshape the DataFrame from a wide table to a long table
`std`	Returns the standard deviation of the values in the specified axis
`sum`	Returns the sum of the values in the specified axis
`sub`	Subtracts the values of a DataFrame with the specified value(s)
`swaplevel`	Swaps the two specified levels
`T`	Turns rows into columns and columns into rows
`tail`	Returns the headers and the last rows
`take`	Returns the specified elements
`to_xarray`	Returns an xarray object
`transform`	Execute a function for each value in the DataFrame
`transpose`	Turns rows into columns and columns into rows
`truediv`	Divides the values of a DataFrame with the specified value(s)
`truncate`	Removes elements outside of a specified set of values
`update`	Update one DataFrame with the values from another DataFrame
`value_counts`	Returns the number of unique rows
`values`	Returns the DataFrame as a NumPy array
`var`	Returns the variance of the values in the specified axis
`where`	Replace all values where the specified condition is False
`xs`	Returns the cross-section of the DataFrame

A.9 `Numpy` Reference

A.9.1 Numpy Data Types

Table A.9

Type	Description
`bool_`	Boolean (True or False) stored as a byte
`int_`	Default integer type (same as C long; normally either int64 or int32)
`intc`	Identical to C int (normally int32 or int64)
`intp`	Integer used for indexing (same as C ssize_t; normally either int32 or int64)
`int8`	Byte (-128 to 127)
`int16`	Integer (-32768 to 32767)
`int32`	Integer (-2147483648 to 2147483647)
`int64`	Integer (-9223372036854775808 to 9223372036854775807)
`uint8`	Unsigned integer (0 to 255)
`uint16`	Unsigned integer (0 to 65535)
`uint32`	Unsigned integer (0 to 4294967295)
`uint64`	Unsigned integer (0 to 18446744073709551615)
`float_`	Shorthand for float64.
`float16`	Half precision float: sign bit, 5 bits exponent, 10 bits mantissa
`float32`	Single precision float: sign bit, 8 bits exponent, 23 bits mantissa
`float64`	Double precision float: sign bit, 11 bits exponent, 52 bits mantissa
`complex_`	Shorthand for complex128.
`complex64`	Complex number, represented by two 32-bit floats
`complex128`	Complex number, represented by two 64-bit floats

A.9.2 Numpy `ufuncs`

Table A.10: List of ufunc which perform standard mathematical operations

ufunc and signature	Description
add(x1, x2, /[, out, where, casting, order, …])	Add arguments element-wise.
subtract(x1, x2, /[, out, where, casting, …])	Subtract arguments, element-wise.
multiply(x1, x2, /[, out, where, casting, …])	Multiply arguments element-wise.
matmul(x1, x2, /[, out, casting, order, …])	Matrix product of two arrays.
divide(x1, x2, /[, out, where, casting, …])	Divide arguments element-wise.
logaddexp(x1, x2, /[, out, where, casting, …])	Logarithm of the sum of exponentiations of the inputs.
logaddexp2(x1, x2, /[, out, where, casting, …])	Logarithm of the sum of exponentiations of the inputs in base-2.
true_divide(x1, x2, /[, out, where, …])	Divide arguments element-wise.
floor_divide(x1, x2, /[, out, where, …])	Return the largest integer smaller or equal to the division of the inputs.
negative(x, /[, out, where, casting, order, …])	Numerical negative, element-wise.
positive(x, /[, out, where, casting, order, …])	Numerical positive, element-wise.
power(x1, x2, /[, out, where, casting, …])	First array elements raised to powers from second array, element-wise.
float_power(x1, x2, /[, out, where, …])	First array elements raised to powers from second array, element-wise.
remainder(x1, x2, /[, out, where, casting, …])	Returns the element-wise remainder of division.
mod(x1, x2, /[, out, where, casting, order, …])	Returns the element-wise remainder of division.
fmod(x1, x2, /[, out, where, casting, …])	Returns the element-wise remainder of division.
divmod(x1, x2[, out1, out2], / [, out, …])	Return element-wise quotient and remainder simultaneously.
absolute(x, /[, out, where, casting, order, …])	Calculate the absolute value element-wise.
fabs(x, /[, out, where, casting, order, …])	Compute the absolute values element-wise.
rint(x, /[, out, where, casting, order, …])	Round elements of the array to the nearest integer.
sign(x, /[, out, where, casting, order, …])	Returns an element-wise indication of the sign of a number.
heaviside(x1, x2, /[, out, where, casting, …])	Compute the Heaviside step function.
conj(x, /[, out, where, casting, order, …])	Return the complex conjugate, element-wise.
conjugate(x, /[, out, where, casting, …])	Return the complex conjugate, element-wise.
exp(x, /[, out, where, casting, order, …])	Calculate the exponential of all elements in the input array.
exp2(x, /[, out, where, casting, order, …])	Calculate 2**p for all p in the input array.
log(x, /[, out, where, casting, order, …])	Natural logarithm, element-wise.
log2(x, /[, out, where, casting, order, …])	Base-2 logarithm of x.
log10(x, /[, out, where, casting, order, …])	Return the base 10 logarithm of the input array, element-wise.
expm1(x, /[, out, where, casting, order, …])	Calculate exp(x) - 1 for all elements in the array.
log1p(x, /[, out, where, casting, order, …])	Return the natural logarithm of one plus the input array, element-wise.
sqrt(x, /[, out, where, casting, order, …])	Return the non-negative square-root of an array, element-wise.
square(x, /[, out, where, casting, order, …])	Return the element-wise square of the input.
cbrt(x, /[, out, where, casting, order, …])	Return the cube-root of an array, element-wise.
reciprocal(x, /[, out, where, casting, …])	Return the reciprocal of the argument, element-wise.
gcd(x1, x2, /[, out, where, casting, order, …])	Returns the greatest common divisor of \|x1\| and \|x2\|
lcm(x1, x2, /[, out, where, casting, order, …])	Returns the lowest common multiple of \|x1\| and \|x2\|

Table A.11: List of ufuncs which perform boolean operations

ufunc and signature	Description
greater(x1, x2, /[, out, where, casting, …])	Return the truth value of (x1 > x2) element-wise.
greater_equal(x1, x2, /[, out, where, …])	Return the truth value of (x1 >= x2) element-wise.
less(x1, x2, /[, out, where, casting, …])	Return the truth value of (x1 < x2) element-wise.
less_equal(x1, x2, /[, out, where, casting, …])	Return the truth value of (x1 <= x2) element-wise.
not_equal(x1, x2, /[, out, where, casting, …])	Return (x1 != x2) element-wise.
equal(x1, x2, /[, out, where, casting, …])	Return (x1 == x2) element-wise.
logical_and(x1, x2, /[, out, where, …])	Compute the truth value of x1 AND x2 element-wise.
logical_or(x1, x2, /[, out, where, casting, …])	Compute the truth value of x1 OR x2 element-wise.
logical_xor(x1, x2, /[, out, where, …])	Compute the truth value of x1 XOR x2, element-wise.
logical_not(x, /[, out, where, casting, …])	Compute the truth value of NOT x element-wise.
maximum(x1, x2, /[, out, where, casting, …])	Element-wise maximum of array elements
minimum(x1, x2, /[, out, where, casting, …])	Element-wise minimum of array elements.
fmax(x1, x2, /[, out, where, casting, …])	Element-wise maximum of array elements.
fmin(x1, x2, /[, out, where, casting, …])	Element-wise minimum of array elements.
isfinite(x, /[, out, where, casting, order, …])	Test element-wise for finiteness (not infinity and not Not a Number).
isinf(x, /[, out, where, casting, order, …])	Test element-wise for positive or negative infinity.
isnan(x, /[, out, where, casting, order, …])	Test element-wise for NaN and return result as a boolean array.
isnat(x, /[, out, where, casting, order, …])	Test element-wise for NaT (not a time) and return result as a boolean array.

Table A.12: List of ufuncs which perform trigonometry operations

ufunc and signature	Description
sin(x, /[, out, where, casting, order, …])	Trigonometric sine, element-wise.
cos(x, /[, out, where, casting, order, …])	Cosine element-wise.
tan(x, /[, out, where, casting, order, …])	Compute tangent element-wise.
arcsin(x, /[, out, where, casting, order, …])	Inverse sine, element-wise.
arccos(x, /[, out, where, casting, order, …])	Trigonometric inverse cosine, element-wise.
arctan(x, /[, out, where, casting, order, …])	Trigonometric inverse tangent, element-wise.
arctan2(x1, x2, /[, out, where, casting, …])	Element-wise arc tangent of x1/x2 choosing the quadrant correctly.
hypot(x1, x2, /[, out, where, casting, …])	Given the “legs” of a right triangle, return its hypotenuse.
sinh(x, /[, out, where, casting, order, …])	Hyperbolic sine, element-wise.
cosh(x, /[, out, where, casting, order, …])	Hyperbolic cosine, element-wise.
tanh(x, /[, out, where, casting, order, …])	Compute hyperbolic tangent element-wise.
arcsinh(x, /[, out, where, casting, order, …])	Inverse hyperbolic sine element-wise.
arccosh(x, /[, out, where, casting, order, …])	Inverse hyperbolic cosine, element-wise.
arctanh(x, /[, out, where, casting, order, …])	Inverse hyperbolic tangent element-wise.
degrees(x, /[, out, where, casting, order, …])	Convert angles from radians to degrees.
radians(x, /[, out, where, casting, order, …])	Convert angles from degrees to radians.
deg2rad(x, /[, out, where, casting, order, …])	Convert angles from degrees to radians.
rad2deg(x, /[, out, where, casting, order, …])	Convert angles from radians to degrees.

Table A.13: List of miscillaneous ufuncs

ufunc and signature	Description
fabs(x, /[, out, where, casting, order, …])	Compute the absolute values element-wise.
signbit(x, /[, out, where, casting, order, …])	Returns element-wise True where signbit is set (less than zero).
copysign(x1, x2, /[, out, where, casting, …])	Change the sign of x1 to that of x2, element-wise.
nextafter(x1, x2, /[, out, where, casting, …])	Return the next floating-point value after x1 towards x2, element-wise.
spacing(x, /[, out, where, casting, order, …])	Return the distance between x and the nearest adjacent number.
modf(x[, out1, out2], / [[, out, where, …])	Return the fractional and integral parts of an array, element-wise.
ldexp(x1, x2, /[, out, where, casting, …])	Returns x1 * 2**x2, element-wise.
frexp(x[, out1, out2], / [[, out, where, …])	Decompose the elements of x into mantissa and twos exponent.
fmod(x1, x2, /[, out, where, casting, …])	Returns the element-wise remainder of division.
floor(x, /[, out, where, casting, order, …])	Return the floor of the input, element-wise.
ceil(x, /[, out, where, casting, order, …])	Return the ceiling of the input, element-wise.
trunc(x, /[, out, where, casting, order, …])	Return the truncated value of the input, element-wise

A.9.3 `ndarray` Attributes and Methods

Table A.14: Attributes that describe details about the memory layout of the data

Attribute	Description
`ndarray.flags`	Information about the memory layout of the array.
`ndarray.shape`	Tuple of array dimensions.
`ndarray.strides`	Tuple of bytes to step in each dimension when traversing an array.
`ndarray.ndim`	Number of array dimensions.
`ndarray.data`	Python buffer object pointing to the start of the array’s data.
`ndarray.size`	Number of elements in the array.
`ndarray.itemsize`	Length of one array element in bytes.
`ndarray.nbytes`	Total bytes consumed by the elements of the array.
`ndarray.base`	Base object if memory is from some other object.

Table A.15: Attributes describing details of the data stored in the array

Attribute	Description
`ndarray.dtype`	Data-type of the array’s elements.
`ndarray.T`	View of the transposed array.
`ndarray.real`	The real part of the array.
`ndarray.imag`	The imaginary part of the array.
`ndarray.flat`	A 1-D iterator over the array.

Table A.16: Methods for converting data within the array

Method	Description
`ndarray.item`(*args)	Copy an element of an array to a standard Python scalar and return it.
`ndarray.tolist`()	Return the array as an `a.ndim`-levels deep nested list of Python scalars.
`ndarray.tobytes`([order])	Construct Python bytes containing the raw data bytes in the array.
`ndarray.tofile`(fid, /[, sep, format])	Write array to a file as text or binary (default).
`ndarray.dump`(file)	Dump a pickle of the array to the specified file.
`ndarray.dumps`()	Returns the pickle of the array as a string.
`ndarray.astype`(dtype[, order, casting, …])	Copy of the array, cast to a specified type.
`ndarray.byteswap`([inplace])	Swap the bytes of the array elements
`ndarray.copy`([order])	Return a copy of the array.
`ndarray.view`([dtype][, type])	New view of array with the same data.
`ndarray.getfield`(dtype[, offset])	Returns a field of the given array as a certain type.
`ndarray.setflags`([write, align, uic])	Set array flags WRITEABLE, ALIGNED, WRITEBACKIFCOPY, respectively.
`ndarray.fill`(value)	Fill the array with a scalar value.

Table A.17: Methods for manipulating the shape of the array

Method	Description
`ndarray.reshape`(a.reshape)	Returns an array containing the same data with a new shape.
`ndarray.resize`(a.resize)	Change shape and size of array in-place.
`ndarray.transpose`(*axes)	Returns a view of the array with axes transposed.
`ndarray.swapaxes`(axis1, axis2, /)	Return a view of the array with axis1 and axis2 interchanged.
`ndarray.flatten`([order])	Return a copy of the array collapsed into one dimension.
`ndarray.ravel`([order])	Return a flattened array.
`ndarray.squeeze`([axis])	Remove axes of length one from a.

Table A.18: Methods for selecting and manipulating data within the array

Method	Description
`ndarray.take`(indices[, axis, out, mode])	Return an array formed from the elements of a at the given indices.
`ndarray.put`(indices, values[, mode])	Set `a.flat[n] = values[n]` for all `n` in indices.
`ndarray.repeat`(repeats[, axis])	Repeat elements of an array.
`ndarray.choose`(choices[, out, mode])	Use an index array to construct a new array from a set of choices.
`ndarray.sort`([axis, kind, order, stable, …])	Sort an array in-place.
`ndarray.argsort`([axis, kind, order, stable, …])	Returns the indices that would sort this array.
`ndarray.partition`(kth[, axis, kind, order, …])	Partially sorts the array in such a way that the value of the element in the k-th position is in the position it would be in a sorted array.
`ndarray.argpartition`(kth[, axis, kind, …])	Returns the indices that would partition this array.
`ndarray.searchsorted`(v[, side, sorter])	Find indices where elements of v should be inserted in a to maintain order.
`ndarray.nonzero`()	Return the indices of the elements that are non-zero.
`ndarray.compress`(condition[, axis, out])	Return selected slices of this array along given axis.
`ndarray.diagonal`([offset, axis1, axis2])	Return specified diagonals.

Table A.19: Methods that perform calculations on the data within the array

Method	Description
`ndarray.max`([axis, out, keepdims, initial, …])	Return the maximum along a given axis.
`ndarray.argmax`([axis, out, keepdims])	Return indices of the maximum values along the given axis.
`ndarray.min`([axis, out, keepdims, initial, …])	Return the minimum along a given axis.
`ndarray.argmin`([axis, out, keepdims])	Return indices of the minimum values along the given axis.
`ndarray.clip`([min, max, out])	Return an array whose values are limited to `[min, max]`.
`ndarray.conj`()	Complex-conjugate all elements.
`ndarray.round`([decimals, out])	Return a with each element rounded to the given number of decimals.
`ndarray.trace`([offset, axis1, axis2, dtype, out])	Return the sum along diagonals of the array.
`ndarray.sum`([axis, dtype, out, keepdims, …])	Return the sum of the array elements over the given axis.
`ndarray.cumsum`([axis, dtype, out])	Return the cumulative sum of the elements along the given axis.
`ndarray.mean`([axis, dtype, out, keepdims, where])	Returns the average of the array elements along given axis.
`ndarray.var`([axis, dtype, out, ddof, …])	Returns the variance of the array elements, along given axis.
`ndarray.std`([axis, dtype, out, ddof, …])	Returns the standard deviation of the array elements along given axis.
`ndarray.prod`([axis, dtype, out, keepdims, …])	Return the product of the array elements over the given axis
`ndarray.cumprod`([axis, dtype, out])	Return the cumulative product of the elements along the given axis.
`ndarray.all`([axis, out, keepdims, where])	Returns True if all elements evaluate to True.
`ndarray.any`([axis, out, keepdims, where])	Returns True if any of the elements of a evaluate to True.

A.1 Built-in Keywords

A.2 Built-in Functions

A.3 list Methods

A.4 dict Methods

A.5 set Methods

A.6 str Methods

A.7 file Methods

A.8 DataFrame Methods

A.9 Numpy Reference