Pyxa Environment

Pyxa is a special subset of Python which is highly optimized for security and privacy. The syntax of the language is not modified from Python2.7. But, the runtime semantics are slightly different.

Runtime Environment

Built-in Data Structures

dict, set, list, tuple are all supported.

Global Reference

In order to use global references, you have to define your variable like this:

a = "my value"
global a
@taxa.route("/my_url")
def myFunc():
    response.add(a)

Global references have to be explicitly declared. You can also do this:

a = "my value"
@taxa.route("/my_url")
def myFunc():
    global a
    response.add(a)

Import

Dynamic imports are not supported since tServices only support single file mode in the devnet. Besides that, the developer can only import the supported libraries mentioned below.

Warning: Importing an unsupported module will cause a run-time error.

Return Size

In the devnet, each tService request and response cannot contain more than 8KB of data in the "data" section. For example:

@taxa.route("/my_url")
def myFunc():
    response.add("8KB OF DATA")

Helper Functions

global h
def h():
    return h2()

global h2
def h2():
    return "h2 called"    

@taxa.route("/")
def f():
    response.add(h())

Helper functions also need to obey the global reference rules.

Built-in Types

  • int() - Integer
  • unicode() - Unicode string
  • str() - Non-Unicode string
  • dict() - Dictionary
  • long() - Long Integer
  • set() - Collections with automatically removed duplicates
  • list() - General collections. Unlike tuple, these collections can be extended after initializing. Individual items can also be changed.
  • bytearray() - Return a new array of bytes
  • float() - An integer with a decimal part
  • tuple() - A list that can't have its size changed after initialization. Often used as an optimized list.
  • bool() - Evaluates input to either True or False

Built-in Functions

  • abs() - Absolute value
>>> abs(-3)
3
<<< abs(3)
3
  • divmod() - division with remainder
>>> divmod(7, 2)
(3, 1)
  • input() - Not implemented
  • open() - Not implemented
  • staticmethod() - Turns a class method from an instance method into a method on the class itself. Usually used as a decorator. The method does not need the "self" argument.
class Test(object):
    def instance_method(self):
        return 'i'

    @staticmethod
    def static():
        return 's'

>>> t = Test()
>>> t.instance_method()
'i'
>>> t.static()
's'
>>> Test.static()
's'
>>> Test.instance_method()
TypeError: instance_method() missing 1 required positional argument: 'self'
  • all() - Returns True if all the items passed in collection evaluate to True.
>>> all([1, 1, 1, 1, 1, 1])
True
>>> all([1, 1, 1, 0, 1, 1])
False
  • enumerate() - Adds a ordinal to each item in an iterable. Most commonly used when iterating through a collection and you want to keep count while doing so.
>>> enumerate(['a', 'b', 'c'])
[(0, 'a'), (1, 'b'), (2, 'c')]
  • ord() - The reverse of chr(). Returns an integer corresponding to the passed in character.
  • any() - Similar to all(), except it returns True if any item evaluates to True.
  • eval() - Not Implemented
  • isinstance() - Returns True if the first argument is an instance of the second argument (which should always be a class).
>>> isinstance(4, int)
True
  • pow() - Raise first argument to the power of the second argument
>>> pow(3, 2)
9
  • sum() - Adds up all numbers in the collection passed in
>>> sum([1, 2, 3, 4, 5])
15
  • basestring() - This abstract type is the superclass for str and unicode. It cannot be called or instantiated, but it can be used to test whether an object is an instance of str or unicode. isinstance(obj, basestring) is equivalent to isinstance(obj, (str, unicode)).
  • execfile() - Not implemented
  • issubclass() - Return True if class is a subclass (direct, indirect or virtual) of classinfo. A class is considered a subclass of itself. classinfo may be a tuple of class objects, in which case every entry in classinfo will be checked. In any other case, a TypeError exception is raised.
  • print() - Not implemented
  • super() - Calls to the superclass implementation
  • bin() - Returns a string of the binary representation of the passed in integer. The result always starts with "0b".
>>> bin(97656)
'0b10111110101111000'
  • file() - Constructor function for the file type. The constructor’s arguments are the same as those of the open() built-in function.
  • iter() - Return an iterator object
  • property() - Return a property attribute for new-style classes (classes that derive from object)
  • filter() - Construct a list from those elements of iterable for which function returns True
  • len() - Returns the length of the passed-in collection
>>> len([1,2,3,4])
4
  • range() - Generates a list of integers
>>> range(2, 8)
[2, 3, 4, 5, 6, 7]
>>> range(2, 8, 2)
[2, 4, 6]
  • type() - Returns the type of the passed-in object
>>> type(3) is int
True
  • raw_input() - Not implemented
  • unichr() - Return the Unicode string of one character whose Unicode code is the integer i.
  • callable() - Return True if the object argument appears callable, False if not.
  • format() - Convert a value to a “formatted” representation, as controlled by format_spec.
  • locals() - Update and return a dictionary representing the current local symbol table.
  • reduce() - Apply function of two arguments cumulatively to the items of iterable, from left to right, so as to reduce the iterable to a single value.
  • chr() - Return a string of one character whose ASCII code is the integer i.
  • frozenset() - Return a new frozenset object, optionally with elements taken from iterable. frozenset is a built-in class.
 class frozenset([iterable])
  • reload() - Reload a previously imported module.
  • vars() - Return the __dict__ attribute for a module, class, instance, or any other object with a __dict__ attribute.
  • classmethod() - Return a class method for function.
  • getattr() - Return the value of the named attribute of object. name must be a string.
  • map() - Applies a callable to each item in collection in the second argument.
>>> map(lambda x: x * 2, [5, 6, 7, 8])
[10, 12, 14, 16]
>>>

Also, maps can be expressed as list comprehensions:

>>> [x * 2 for x in [5, 6, 7, 8]]
[10, 12, 14, 16]
>>>
  • repr() - Return a string containing a printable representation of an object.
  • xrange() - Like range() but returns an iterator instead of just a list.
  • cmp() - Compare the two objects x and y and return an integer according to the outcome.
  • globals() - Return a dictionary representing the current global symbol table.
  • max() - Returns the maximum value from the collection passed in.
>>> max([6,5,4,3])
6
  • reversed() - Return a reverse iterator.
  • zip() - This function returns a list of tuples, where the i-th tuple contains the i-th element from each of the argument sequences or iterables.
  • compile() - Compile the source into a code or AST object.
  • hasattr() - The arguments are an object and a string. The result is True if the string is the name of one of the object’s attributes, False if not.
  • memoryview() - Return a “memory view” object created from the given argument.
  • round() - Return the floating point value number rounded to ndigits digits after the decimal point.
  • _import__() - The function imports the module name, potentially using the given globals and locals to determine how to interpret the name in a package context.
__import__(name[, globals[, locals[, fromlist[, level]]]])
  • complex() - Return a complex number with the value real + imag1j or convert a string or number to a complex number.
  • hash() - Return the hash value of the object (if it has one).
  • min() - Returns the minimum value from the collection passed in.
>>> min([6,5,4,3])
3
  • delattr() - This is a relative of setattr(). The arguments are an object and a string.
  • help() - Invoke the built-in help system.
  • next() - Retrieve the next item from the iterator by calling its next() method.
  • setattr() - This is the counterpart of getattr(). The arguments are an object, a string and an arbitrary value.
  • hex() - Convert an integer number (of any size) to a lowercase hexadecimal string prefixed with "0x".
   >>> hex(255)
   '0xff'
   >>> hex(-42)
   '-0x2a'
   >>> hex(1L)
   '0x1L'
  • object() - Return a new featureless object. object is a base for all new style classes.
  • slice() - Return a slice object representing the set of indices specified by range(start, stop, step).
  • dir() - Without arguments, return the list of names in the current local scope. With an argument, attempt to return a list of valid attributes for that object.
  • id() - Return the “identity” of an object.
  • oct() - Convert an integer number (of any size) to an octal string.
  • sorted() - Returns a copy of the passed in list sorted.
>>> sorted([9,4,1,8,4,6])
[1, 4, 4, 6, 8, 9]

keywords

  • False
  • await
  • else
  • import
  • pass
  • None
  • break
  • except
  • in
  • raise
  • True
  • class
  • finally
  • is
  • return
  • and
  • continue
  • for
  • lambda
  • try
  • as
  • def
  • from
  • nonlocal
  • while
  • assert
  • del
  • global
  • not
  • with
  • async
  • elif
  • if
  • or
  • yield
global gen
def gen():
    yield 1
    yield 2
    yield 'x'

@taxa.route("/f")
def f():
    response.add(str(list(gen())))  # [1, 2, 'x']