Python Functions.txt

FUNCTIONS USED IN NUMBERS
append() - 		Add an element to the end of the list
extend() - 		Add all elements of a list to the another list
insert() -    	        Insert an item at the defined index
remove() - 		Removes an item from the list
pop() - 			Removes and returns an element at the given index
clear() -			 Removes all items from the list
index() - 			Returns the index of the first matched item
count() -			 Returns the count of number of items passed as an argument
sort() - 			Sort items in a list in ascending order
reverse() -		 Reverse the order of items in the list
copy() -		    	 Returns a shallow copy of the list

BUILT-IN FUNCTIONS WITH LIST
all()			Return True if all elements of the list are true (or if the list is empty).
any()		Return True if any element of the list is true. If the list is empty, return False.
enumerate()	Return an enumerate object. It contains the index and value of all the items of list as a tuple.
len()			Return the length (the number of items) in the list.
list()			Convert an iterable (tuple, string, set, dictionary) to a list.
max()		Return the largest item in the list.
min()		Return the smallest item in the list
sorted()		Return a new sorted list (does not sort the list itself).
sum()		Return the sum of all elements in the list.

TYPECASTING
str() 		 --print(str()+str()) #Joint Statement
int()			 --print(int()+int()) 
float()              --print(float()+float())

FUNCTIONS FOR STRINGS
Python String capitalize()		Converts first character to Capital Letter
Python String center()	                Pads string with specified character
Python String casefold()		converts to casefolded strings
Python String count()			returns occurrences of substring in string
Python String endswith()		Checks if String Ends with the Specified Suffix
Python String expandtabs()		Replaces Tab character With Spaces
Python String encode()			returns encoded string of given string
Python String find()			Returns the index of first occurrence of substring
Python String format()			formats string into nicer output
Python String index()			Returns Index of Substring
Python String isalnum()		Checks Alphanumeric Character
Python String isalpha()			Checks if All Characters are Alphabets
Python String isdecimal()		Checks Decimal Characters
Python String isdigit()			Checks Digit Characters
Python String isidentifier()		Checks for Valid Identifier
Python String islower()			Checks if all Alphabets in a String are Lowercase
Python String isnumeric()		Checks Numeric Characters
Python String isprintable()		Checks Printable Character
Python String isspace()			Checks Whitespace Characters
Python String istitle()			Checks for Titlecased String
Python String isupper()		returns if all characters are uppercase characters
Python String join()			Returns a Concatenated String
Python String ljust()			returns left-justified string of given width
Python String rjust()			returns right-justified string of given width
Python String lower()			returns lowercased string
Python String upper()			returns uppercased string
Python String swapcase()		swap uppercase characters to lowercase; vice versa
Python String lstrip()			Removes Leading Characters
Python String rstrip()			Removes Trailing Characters
Python String strip()			Removes Both Leading and Trailing Characters
Python String partition()		Returns a Tuple
Python String maketrans()		returns a translation table
Python String rpartition()		Returns a Tuple
Python String translate()		returns mapped charactered string
Python String replace()			Replaces Substring Inside
Python String rfind()			Returns the Highest Index of Substring
Python String rindex()			Returns Highest Index of Substring
Python String split()			Splits String from Left
Python String rsplit()			Splits String From Right
Python String splitlines()		Splits String at Line Boundaries
Python String startswith()		Checks if String Starts with the Specified String
Python String title()			Returns a Title Cased String
Python String zfill()			Returns a Copy of The String Padded With Zeros
Python String format_map()	Formats the String Using Dictionary
Python any()					Checks if any Element of an Iterable is True
Python all()					returns true when all elements in iterable is true
Python ascii()					Returns String Containing Printable Representation
Python bool()					Converts a Value to Boolean
Python bytearray()			returns array of given byte size
Python bytes()				returns immutable bytes object
Python compile()				Returns a Python code object
Python complex()				Creates a Complex Number
Python enumerate()			    Returns an Enumerate Object
Python filter()				    constructs iterator from elements which are true
Python float()				    returns floating point number from number, string
Python input()				    reads and returns a line of string
Python int()					returns integer from a number or string
Python iter()					returns iterator for an object
Python len()					Returns Length of an Object
Python max()					returns largest element
Python min()					returns smallest element
Python map()					Applies Function and Returns a List
Python ord()					returns Unicode code point for Unicode character
Python reversed()				returns reversed iterator of a sequence
Python slice()					creates a slice object specified by range()
Python sorted()				    returns sorted list from a given iterable
Python sum()					Add items of an Iterable
Python zip()					Returns an Iterator of Tuples

DICTIONARY F() IN PYTHON
clear()			Remove all items form the dictionary.
copy()			Return a shallow copy of the dictionary.
fromkeys(seq[, v])	Return a new dictionary with keys from seq and value equal to v (defaults to None).
get(key[,d])		Return the value of key. If key doesnot exit, return d (defaults to None).
items()			Return a new view of the dictionary's items (key, value).
keys()			Return a new view of the dictionary's keys.
pop(key[,d])		Remove the item with key and return its value or d if key is not found. If d is not provided and key is not found, 				raises KeyError.
popitem()		Remove and return an arbitary item (key, value). Raises KeyError if the dictionary is empty.
setdefault(key[,d])	If key is in the dictionary, return its value. If not, insert key with a value of d and return d (defaults to None).
update([other])	Update the dictionary with the key/value pairs from other, overwriting existing keys.
values()			Return a new view of the dictionary's values

TYPES OF OPERATORS IN PYTHON LANGUAGE
Arithmetic Operators
Comparison (Relational) Operators
Assignment Operators
Logical Operators
Bitwise Operators
Membership Operators
Identity Operators

FILE IO BASICS
1. file.close()				It closes the opened file. The file once closed, it can?t be read or write any more.
2. File.fush()				It flushes the internal buffer.
3. File.fileno()				It returns the file descriptor used by the underlying implementation to request I/O from the OS.
4. File.isatty()				It returns true if the file is connected to a TTY device, otherwise returns false.
5. File.next()				It returns the next line from the file.
6. nFile.read([size])		It reads the file for the specified size.
7. File.readline([size])		It reads one line from the file and places the file pointer to the beginning of the new line.
8. File.readlines([sizehint])	It returns a list containing all the lines of the file. It reads the file until the EOF occurs using readline() 								function.
9. File.seek(offset[,from)	It modifies the position of the file pointer to a specified offset with the specified reference.
10. File.tell()				It returns the current position of the file pointer within the file.
11. File.truncate([size]	)	It truncates the file to the optional specified size.
12. File.write(str)			It writes the specified string to a file
13. File.writelines(seq)		It writes a sequence of the strings to a file.

FILE MODES IN PYTHON
'r'		This is the default mode. It Opens file for reading.
'w'		This Mode Opens file for writing.      If file does not exist, it creates a new file.     If file exists it truncates the file.
'x'		Creates a new file. If file already exists, the operation fails.
'a'		Open file in append mode.          If file does not exist, it creates a new file
't'		This is the default mode. It opens in text mode.
'b'		This opens in binary mode.
'+'		This will open a file for reading and writing (updating)

WRITING A FILE
write() : 			 Inserts the string str1 in a single line in the text file.
writelines() : 		 For a list of string elements, each string is inserted in the text file.Used to insert multiple strings at a single time.
read() :			 Returns the read bytes in form of a string. Reads n bytes, if no n specified, reads the entire file.
readline() :		 Reads a line of the file and returns in form of a string.For specified n, reads at most n bytes. However, does not 				reads more than one line, even if n exceeds the length of the line.
readlines() :		 Reads all the lines and return them as each line a string element in a list.

ESCAPE SEQUENCE IN PYTHON
\\			Prints Backslash	
\`			Prints single-quote	
\"			Pirnts double quote
\a			ASCII bell makes ringing the bell alert sounds ( eg. xterm )	
\b			ASCII backspace ( BS ) removes previous character	
\f			ASCII formfeed ( FF )	
\n			ASCII linefeed ( LF )	
\N{name}	Prints a character from the Unicode database	
\r			ASCII carriage return (CR). Moves all characters after ( CR ) the the beginning of the line while overriding same number 			of characters moved.	
\t			ASCII horizontal tab (TAB). Prints TAB	
\t			ASCII vertical tab (VT).	
\uxxxx		Prints 16-bit hex value Unicode character	
\Uxxxxxxxx	Prints 32-bit hex value Unicode character	
\ooo		Prints character based on its octal value	
\xhh		Prints character based on its hex value	print 
  
PRINT()PAPAMETERS
objects - object to the printed. * indicates that there may be more than one object
sep - objects are separated by sep. Default value: ' '
end - end is printed at last
file - must be an object with write(string) method. If omitted it, sys.stdout will be used which prints objects on the screen.
flush - If True, the stream is forcibly flushed. Default value: False