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Python - Coggle Diagram

- - - - There can be zero or more elif parts, and the else part is optional.
  - - - def fib2(n): # return Fibonacci series up to n
        """Return a list containing the Fibonacci series up to n."""
        result = []
        a, b = 0, 1
        while a < n:
        result.append(a) # see below
        a, b = b, a+b
        return result
        f100 = fib2(100) # call it
        f100 # write the result
        [0,1,1,2,3,5,8,13,21,34,55,89]
- - - - str()
        
        Returns a string object
        
        strings
        
        use r before the first quote for using \ in output
        
        Strings can be concatenated (glued together) with the + operator, and repeated with *
        
        If you want to concatenate variables or a variable and a literal, use +:
        
        'prefix' + 'thon'
        'Python'
        
        slicing
        
        first character having index 0, word = 'Python' word[0] # character in position 0
        
        Indices may also be negative numbers, to start counting from the right:
        
        word[-1] # last character
        'n'
        
        individual characters, slicing
        
        word[0:2] # characters from position 0 (included) to 2 (excluded)
        'Py'
        
        1 more item...
        
        word[2:5] # characters from position 2 (included) to 5 (excluded)
        'tho'
        
        1 more item...
        
        Python strings cannot be changed — they are immutable.
        
        If you need a different string, you should create a new one:
        
        'J' + word[1:]
        'Jython'
        word[:2] + 'py'
        'Pypy'
        
        use \n for newline only with print command
        
        len() returns the length of a string:
        
        s = 'supercalifragilisticexpialidocious' >>> len(s) 34
        
        make a string with " ...." or '.......'
        
        use \' for escape he single quote
        
        use print() for print your output
        
        built-in methods that you can use on strings.
        
        isupper()
        
        Returns True if all characters in the string are upper case
        
        join()
        
        Joins the elements of an iterable to the end of the string
        
        istitle()
        
        Returns True if the string follows the rules of a title
        
        ljust()
        
        Returns a left justified version of the string
        
        isspace()
        
        Returns True if all characters in the string are whitespaces
        
        lower()
        
        Converts a string into lower case
        
        isprintable()
        
        Returns True if all characters in the string are printable
        
        lstrip()
        
        Returns a left trim version of the string
        
        isnumeric()
        
        Returns True if all characters in the string are numeric
        
        maketrans()
        
        Returns a translation table to be used in translations
        
        islower()
        
        Returns True if all characters in the string are lower case
        
        partition()
        
        Returns a tuple where the string is parted into three parts
        
        isidentifier()
        
        Returns True if the string is an identifier
        
        replace()
        
        Returns a string where a specified value is replaced with a specified value
        
        isdigit()
        
        Returns True if all characters in the string are digits
        
        rfind()
        
        Searches the string for a specified value and returns the last position of where it was found
        
        isdecimal()
        
        Returns True if all characters in the string are decimals
        
        rindex()
        
        Searches the string for a specified value and returns the last position of where it was found
        
        isalpha()
        
        Returns True if all characters in the string are in the alphabet
        
        rjust()
        
        Returns a right justified version of the string
        
        isalnum()
        
        Returns True if all characters in the string are alphanumeric
        
        split()
        
        Splits the string at the specified separator, and returns a list
        
        index()
        
        Searches the string for a specified value and returns the position of where it was found
        
        splitlines()
        
        Splits the string at line breaks and returns a list
        
        format_map()
        
        Formats specified values in a string
        
        startswith()
        
        Returns true if the string starts with the specified value
        
        format()
        
        Formats specified values in a string
        
        find()
        
        Searches the string for a specified value and returns the position of where it was found
        
        expandtabs()
        
        Sets the tab size of the string
        
        endswith()
        
        Returns true if the string ends with the specified value
        
        encode()
        
        Returns an encoded version of the string
        
        count()
        
        Returns the number of times a specified value occurs in a string
        
        center()
        
        Returns a centered string
        
        casefold()
        
        Converts string into lower case
        
        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
        
        capitalize()
        
        Converts the first character to upper case
        
        str.join()
        
        io.StringIO
        
        str.capitalize()
        
        Return a copy of the string with its first character capitalized and the rest lowercased.
        
        str.casefold()
        
        Return a casefolded copy of the string. Casefolded strings may be used for caseless matching.
        Casefolding is similar to lowercasing but more aggressive because it is intended to remove all case distinctions in a string. For example, the German lowercase letter 'ß' is equivalent to "ss". Since it is already lowercase, lower() would do nothing to 'ß'; casefold() converts it to "ss".
        
        str.center(width[, fillchar])
        
        Return centered in a string of length width. Padding is done using the specified fillchar (default is an ASCII space). The original string is returned if width is less than or equal to len(s).
        
        str.count(sub[, start[, end]])
        
        Return the number of non-overlapping occurrences of substring sub in the range [start, end]. Optional arguments start and end are interpreted as in slice notation.
        
        str.find(sub[, start[, end]])
        
        Return the lowest index in the string where substring sub is found within the slice s[start:end]. Optional arguments start and end are interpreted as in slice notation. Return -1 if sub is not found.
        
        Note=The find() method should be used only if you need to know the position of sub. To check if sub is a substring or not, use the in operator:
        
        'Py' in 'Python'
        True
        
        formatting
        
        str.format(args, *kwargs)
        
        if you want to put different variables in your string and you don't want to use + in it then you can you formating option
        
        "The sum of 1 + 2 is {0}".format(1+2)
        'The sum of 1 + 2 is 3'
        
        str.format_map(mapping)
        
        Similar to str.format(**mapping), except that mapping is used directly and not copied to a dict. This is useful if for example mapping is a dict subclass:
        
        class Default(dict):
        def missing(self, key):
        return key
        '{name} was born in {country}'.format_map(Default(name='Guido'))
        'Guido was born in country'
        
        str.index(sub[, start[, end]])
        
        Like find(), but raise ValueError when the substring is not found.
        
        some useful sintex with (is)
        
        str.isalnum()
        
        Return True if all characters in the string are alphanumeric and there is at least one character,
        
        A character c is alphanumeric if one of the following returns True: c.isalpha(), c.isdecimal(), c.isdigit(), or c.isnumeric().
        
        str.isalpha(
        
        Return True if all characters in the string are alphabetic and there is at least one character
        
        str.isascii()
        
        Return True if the string is empty or all characters in the string are ASCII
        
        str.isdecimal()
        
        Return True if all characters in the string are decimal characters and there is at least one character,
        
        str.isdigit()
        
        Return True if all characters in the string are digits and there is at least one character,
        
        str.isidentifier()
        
        Return True if the string is a valid identifier according to the language definition, section Identifiers and keywords.
        
        from keyword import iskeyword
        'hello'.isidentifier(), iskeyword('hello')
        True, False
        'def'.isidentifier(), iskeyword('def')
        True, True
        
        str.islower()
        
        Return True if all cased characters 4 in the string are lowercase and there is at least one cased character
        
        str.isnumeric()
        
        Return True if all characters in the string are numeric characters, and there is at least one character
        
        str.isprintable()
        
        Return True if all characters in the string are printable or the string is empty,
        
        str.isspace()
        
        Return True if there are only whitespace characters in the string and there is at least one character
        
        str.istitle()
        
        Return True if the string is a titlecased string and there is at least one character, for example uppercase characters may only follow uncased characters and lowercase characters only cased ones.
        
        str.isupper()
        
        Return True if all cased characters 4 in the string are uppercase and there is at least one cased character, False otherwise.
        
        str.lower()
        
        Return a copy of the string with all the cased characters 4 converted to lowercase
        
        str.lstrip([chars])
        
        Return a copy of the string with leading characters removed. The chars argument is a string specifying the set of characters to be removed. If omitted or None, the chars argument defaults to removing whitespace. The chars argument is not a prefix; rather, all combinations of its values are stripped:
        
        ' spacious '.lstrip()
        'spacious '
        'www.example.com'.lstrip('cmowz.')
        'example.com'
        
        str.ljust(width[, fillchar])
        
        static str.maketrans(x[, y[, z]])
        
        str.partition(sep)
        
        Split the string at the first occurrence of sep, and return a 3-tuple containing the part before the separator, the separator itself, and the part after the separator. If the separator is not found, return a 3-tuple containing the string itself, followed by two empty strings.
        
        str.replace(old, new[, count])
        
        Return a copy of the string with all occurrences of substring old replaced by new. If the optional argument count is given, only the first count occurrences are replaced.
        
        some useful commands with r
        
        str.rfind(sub[, start[, end]])
        
        Return the highest index in the string where substring sub is found, such that sub is contained within s[start:end]. Optional arguments start and end are interpreted as in slice notation. Return -1 on failure.
        
        str.rindex(sub[, start[, end]])
        
        Like rfind() but raises ValueError when the substring sub is not found
        
        str.rjust(width[, fillchar])
        
        Return the string right justified in a string of length width. Padding is done using the specified fillchar (default is an ASCII space). The original string is returned if width is less than or equal to len(s).
        
        str.rstrip([chars])
        
        Return a copy of the string with trailing characters removed. The chars argument is a string specifying the set of characters to be removed. If omitted or None, the chars argument defaults to removing whitespace
        
        str.split(sep=None, maxsplit=-1)
        
        str.splitlines([keepends])
        
        Return a list of the lines in the string, breaking at line boundaries. Line breaks are not included in the resulting list unless keepends is given and true.
        
        str.startswith(prefix[, start[, end]])
        
        Return True if string starts with the prefix, otherwise return False. prefix can also be a tuple of prefixes to look for. With optional start, test string beginning at that position. With optional end, stop comparing string at that position.
        
        str.strip([chars])
        
        Return a copy of the string with the leading and trailing characters removed. The chars argument is a string specifying the set of characters to be removed. If omitted or None, the chars argument defaults to removing whitespace
        
        spacious '.strip() 'spacious'
        'www.example.com'.strip('cmowz.')
        'example'
        
        str.swapcase()
        
        Return a copy of the string with uppercase characters converted to lowercase and vice versa. Note that it is not necessarily true that s.swapcase().swapcase() == s.
        
        str.title()
        
        'Hello world'.title()
        'Hello World'
        
        str.translate(table)
        
        Return a copy of the string in which each character has been mapped through the given translation table. The table must be an object that implements indexing via getitem(),typically a mapping or sequence. When indexed by a Unicode ordinal (an integer), the table object can do any of the following: return a Unicode ordinal or a string, to map the character to one or more other characters; return None, to delete the character from the return string; or raise a LookupError exception, to map the character to itself.You can use str.maketrans() to create a translation map from character-to-character mappings in different formats.
        See also the codecs module for a more flexible approach to custom character mappings.
        
        str.upper(
        
        Return a copy of the string with all the cased characters 4 converted to uppercase
        
        str.zfill(width)
        
        Return a copy of the string left filled with ASCII '0' digits to make a string of length width. A leading sign prefix ('+'/'-') is handled by inserting the padding after the sign character rather than before. The original string is returned if width is less than or equal to len(s).
        
        "42".zfill(5)
        '00042'
        "-42".zfill(5)
        '-0042
      - len()
        
        Returns the length of an object
      - range()
        
        Returns a sequence of numbers, starting from 0 and increments by 1 (by default)
      - 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. Replaces none-ascii characters with escape character
      - 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
      - dict()
        
        Returns a dictionary (Array)
      - dir()
        
        Returns a list of the specified object's properties and methods
      - delattr()
        
        Deletes the specified attribute (property or method) from the specified object
      - complex()
        
        Returns a complex number
      - compile()
        
        Returns the specified source as an object, ready to be executed
      - classmethod()
        
        Converts a method into a class method
      - chr()
        
        Returns a character from the specified Unicode code
      - callable()
        
        Returns True if the specified object is callable, otherwise False
      - enumerate()
        
        Takes a collection (e.g. a tuple) and returns it as an enumerate object
      - divmod()
        
        Returns the quotient and the remainder when argument1 is divided by argument2
      - eval()
        
        Evaluates and executes an expression
      - exec()
        
        Executes the specified code (or object)
      - hasattr()
        
        Returns True if the specified object has the specified attribute (property/method)
      - hash()
        
        Returns the hash value of a specified object
      - globals()
        
        Returns the current global symbol table as a dictionary
      - help()
        
        Executes the built-in help system
      - getattr()
        
        Returns the value of the specified attribute (property or method)
      - hex()
        
        Converts a number into a hexadecimal value
      - frozenset()
        
        Returns a frozenset object
      - id()
        
        Returns the id of an object
      - format()
        
        Formats a specified value
      - input()
        
        Allowing user input
      - float()
        
        Returns a floating point number
      - int()
        
        Returns an integer number
      - filter()
        
        Use a filter function to exclude items in an iterable object
      - isinstance()
        
        Returns True if a specified object is an instance of a specified object
      - map()
        
        Returns the specified iterator with the specified function applied to each item
      - issubclass()
        
        Returns True if a specified class is a subclass of a specified object
      - locals()
        
        Returns an updated dictionary of the current local symbol table
      - iter()
        
        Returns an iterator object
      - list()
        
        Returns a list
      - object()
        
        Returns a new object
      - next()
        
        Returns the next item in an iterable
      - min()
        
        Returns the smallest item in an iterable
      - memoryview()
        
        Returns a memory view object
      - max()
        
        Returns the largest item in an iterable
      - pow()
        
        Returns the value of x to the power of y
      - set()
        
        Returns a new set object
      - round()
        
        Rounds a numbers
      - ord()
        
        Convert an integer representing the Unicode of the specified character
      - open()
        
        Opens a file and returns a file object
      - oct()
        
        Converts a number into an octal
      - repr()
        
        Returns a readable version of an object
      - print()
        
        Prints to the standard output device
      - property()
        
        Gets, sets, deletes a property
      - reversed()
        
        Returns a reversed iterator
      - setattr()
        
        Sets an attribute (property/method) of an
      - sorted()
        
        Returns a sorted list
      - tuple()
        
        Returns a tuple
      - sum()
        
        Sums the items of an iterator
      - zip()
        
        Returns an iterator, from two or more iterators
      - vars()
        
        Returns the dict property of an object
      - staticmethod()
        
        Converts a method into a static method
      - slice()
        
        Returns a slice object
      - type()
        
        Returns the type of an object
      - super()
        
        Returns an object that represents the parent class
  - - - The keyword def introduces a function definition. It must be followed by the function name and the parenthesized list of formal parameters. The statements that form the body of the function start at the next line, and must be indented.
        
        def fib(n): # write Fibonacci series up to n
        """Print a Fibonacci series up to n."""
        a, b = 0, 1
        while a < n:
        print(a, end=' ')
        a, b = b, a+b
        print()
        Now call the function we just defined:
        fib(2000)
        0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597
        
        The interpreter recognizes the object pointed to by that name as a user-defined function.
        
        fib<function fib at 10042ed0>
        f = fib
        f(100)
        0 1 1 2 3 5 8 13 21 34 55 89
        
        you might object that fib is not a function but a procedure since it doesn’t return a value. In fact, even functions without a return statement do return a value,
      - Default Argument Values
- - - - Code that modifies a collection while iterating over that same collection can be tricky to get right. Instead, it is usually more straight-forward to loop over a copy of the collection or to create a new collection:
        
        Strategy: Iterate over a copy
        for user, status in users.copy().items():
        if status == 'inactive':
        del users[user]
        Strategy: Create a new collection
        active_users = {}
        for user, status in users.items():
        if status == 'active':
        active_users[user] = status
    - - If you do need to iterate over a sequence of numbers,
        
        for i in range(5):
        print(i)
        0
        1
        2
        3
        4
        
        range(5, 10) 5, 6, 7, 8, 9
        
        To iterate over the indices of a sequence, you can combine range() and len() as follows
        
        a = ['Mary', 'had', 'a', 'little', 'lamb']
        :for i in range(len(a)):
        print(i, a[i])
        0 Mary
        1 had.
        2 a
        3 little
        4 lamb
- - - - int 1,2,3,4,5,6,7,8,9,.........
      - float 1.23, 65.265 ,33.373673
      - complex i+1, i+2
      - decimal
  - - - built-in methods that you can use on dictionaries.
        
        keys()
        
        Returns a list containing the dictionary's keys
        
        pop()
        
        Removes the element with the specified key
        
        items()
        
        Returns a list containing a tuple for each key value pair
        
        popitem()
        
        Removes the last inserted key-value pair
        
        get()
        
        Returns the value of the specified key
        
        setdefault()
        
        Returns the value of the specified key. If the key does not exist: insert the key, with the specified value
        
        fromkeys()
        
        Returns a dictionary with the specified keys and value
        
        update()
        
        Updates the dictionary with the specified key-value pairs
        
        copy()
        
        Returns a copy of the dictionary
        
        values()
        
        Returns a list of all the values in the dictionary
        
        clear()
        
        Removes all the elements from the dictionary
    - - built-in methods that you can use on tuples.
        
        count()
        
        Returns the number of times a specified value occurs in a tuple
        
        index()
        
        Searches the tuple for a specified value and returns the position of where it was found
    - - built-in methods that you can use on 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
        
        intersection()
        
        Returns a set, that is the intersection of two other sets
        
        issubset()
        
        Returns whether another set contains this set or not
        
        discard()
        
        Remove the specified item
        
        issuperset()
        
        Returns whether this set contains another set or not
        
        difference_update()
        
        Removes the items in this set that are also included in another, specified set
        
        pop()
        
        Removes an element from the set
        
        difference()
        
        Returns a set containing the difference between two or more sets
        
        remove()
        
        Removes the specified element
        
        copy()
        
        Returns a copy of the set
        
        symmetric_difference()
        
        Returns a set with the symmetric differences of two sets
        
        clear()
        
        Removes all the elements from the set
        
        symmetric_difference_update()
        
        inserts the symmetric differences from this set and another
        
        add()
        
        Adds an element to the set
        
        union()
        
        Return a set containing the union of sets
        
        update()
        
        Update the set with the union of this set and others
    - - methods available for the file object.
        
        readline()
        
        Returns one line from the file
        
        readlines()
        
        Returns a list of lines from the file
        
        readable()
        
        Returns whether the file stream can be read or not
        
        seek()
        
        Change the file position
        
        read()
        
        Returns the file content
        
        seekable()
        
        Returns whether the file allows us to change the file position
        
        isatty()
        
        Returns whether the file stream is interactive or not
        
        tell()
        
        Returns the current file position
        
        flush()
        
        Flushes the internal buffer
        
        truncate()
        
        Resizes the file to a specified size
        
        fileno()
        
        Returns a number that represents the stream, from the operating system's perspective
        
        writable()
        
        Returns whether the file can be written to or not
        
        detach()
        
        Returns the separated raw stream from the buffer
        
        write()
        
        Writes the specified string to the file
        
        close()
        
        Closes the file
        
        writelines()
        
        Writes a list of strings to the file
    - - built-in methods that you can use on lists/arrays.
        
        index()
        
        Returns the index of the first element with the specified value
        
        insert()
        
        Adds an element at the specified position
        
        extend()
        
        Add the elements of a list (or any iterable), to the end of the current list
        
        pop()
        
        Removes the element at the specified position
        
        count()
        
        Returns the number of elements with the specified value
        
        remove()
        
        Removes the first item with the specified value
        
        copy()
        
        Returns a copy of the list
        
        reverse()
        
        Reverses the order of the list
        
        clear()
        
        Removes all the elements from the list
        
        sort()
        
        Sorts the list
        
        append()
        
        Adds an element at the end of the list
- - - - To import a module
    - - To check if a value is present in a list, tuple, etc.
    - - To make a conditional statement
    - - To test if two variables are equal
    - - To declare a global variable
    - - To create an anonymous function
    - - To import specific parts of a module
    - - Represents a null value
    - - To create a for loop
    - - To declare a non-local variable
    - - Used with exceptions, a block of code that will be executed no matter if there is an exception or not
    - - A logical operator
    - - Boolean value, result of comparison operations
    - - A logical operator
    - - Used with exceptions, what to do when an exception occurs
    - - A null statement, a statement that will do nothing
    - - Used in conditional statements
    - - To raise an exception
    - - Used in conditional statements, same as else if
    - - To exit a function and return a value
    - - To delete an object
    - - Boolean value, result of comparison operations
    - - To define a function
    - - To make a try...except statement
    - - To continue to the next iteration of a loop
    - - To create a while loop
    - - To define a class
    - - Used to simplify exception handling
    - - To break out of a loop
    - - To end a function, returns a generator
    - - For debugging
    - - To create an alias
    - - A logical operator