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OBJECTS

README.md

FUNCTIONS

CONVERSION

chr(int) : int code to char
hex(int) : int to hex
hexlify(bytes) : bytes to hex
ord(char) : char to int code
bytes.fromhex(str) : return bytes obj from hex string
byte s.hex() : bytes to hex
int(str, base=10) : str to int, in base
int.from_bytes(b, endianness) : bytes to int, with endianness

  •   endianness=”big”|”little”

int.to_bytes(n, endianness) : int to bytes;

  •   n=number of bytes to use for conversion (at least equal to result)  

  •   endianness=”big”|”little”

str.decode(charset=”utf-16”) : bytes to char
str.encode() : char to bytes

STRINGS

FORMAT

b”string” : encoded

OLD

eval(string) : valuta stringa come espressione matematica
sorted(lista...) : ordina

str.endswith(carattere) : bool finisce con
str.join([strings]) :

  • str.len()
    str.lower() : dà tutto lowercase
  • str.partition('c') = 'abcd' -> ['ab','c','d']
    str.replace(e1,e2) :
    str.rfind(substr) : trova substr e dà l'indice più alto (-1 se non trovato)
    string.split() : "Hello World" -> ["Hello","World"
    str.swapcase() : swappa
    str.upper() : dà tutto uppercase
    str.zfill(int n) : prints zeroes before str such that there are at least n characters

NUMBERS

complex() :
float() :
int() :

  • abs(-n) = n (absolute)
  • max()
  • min()
    round(obj) : arrotonda

complex.real() :
complex.imag() :

decimal

decimal : package

Decimal(int): get int of undefined length

DATA STRUCTURES

insieme.count(elem) : conta elem in insieme
len(x) : length
insieme.sort() : bool, se è ordinata

LISTS

list(elements) : convert to list

  • es.: list(range(..))

reduce(function, iterable) :

sum(list, start=0) : sum of elements in list, starting from start parameter+first element,

  • and using the result for the next summation

list.extend(insieme) : aggiunge elem di insieme a list
list.index(elem) : indice dell'elemento
list.insert(index, elem) :
list.pop([index]) : removes and returns element in index (last item if not specified)

DICTIONARIES

dic.get(index, exc=None) : returns value, or exc if not found (instead of error) (=None by default)
.pop(key) : removes key (if present) and returns it

.keys() : list of keys
.items() : list of pairs KEY,VAL
.values() : list of values

I/O

input() :
print(object(s), sep=separator, end=end, file=file, flush=flush) :

  • e.g.: print(“qualcosa”, end = “,”)` : aggiunge end alla fine

MISC

del(var) : delete variable
enumerate(iterable) : return iterator of pairs (number=0,1,.. element[number] of iterable)
type() :
zip() : empty iterator
zip(arg) : return an iterator to tuples, each with one element (from arg),

  •   where arg is an iterable element

zip(args…) : (2+ args) return an iterator to tuples,

  • where tuple i contains the i-th element of each arg (in order);
  • args are iterable;
  • if args of different length, the shortest one is used

CLASSES

super() : refers to base (parent) class (indirection)

obj.__mro__ : Method Resolution Order : order in which methods are inherited

FILE

OPENING

var = open('nome_file', 'mode') : mode = 'r' (default): read, 'w': rewrite (deletes content);

  • file can be accessed/iterated as “list” of rows;
  • (creates a new file if not existing), 'a': append, ‘b’: binary mode
  • (for not-text files, as images, sound) (you can combine modes: es. “wb”)

var.close() : close
var.readlines() : var=list of lines
var.read(int n) : var = string made of n bytes of file (default: all file)
x = var.write('str') : writes str in the file; returns in x number of bytes written

CONSTANTS

__name__ :

  • = “main” if file is being run, else name of the file
    __main__ = name of the file being run