Goku Answers

Saturday 4 November 2017

Help on Python

Help on Python

execute the below command in python shell to launch help tool.

HELP

help()

>>> help()

Welcome to Python 3.6's help utility!

If this is your first time using Python, you should definitely check out
the tutorial on the Internet at http://docs.python.org/3.6/tutorial/.

Enter the name of any module, keyword, or topic to get help on writing
Python programs and using Python modules. To quit this help utility and
return to the interpreter, just type "quit".

To get a list of available modules, keywords, symbols, or topics, type
"modules", "keywords", "symbols", or "topics". Each module also comes
with a one-line summary of what it does; to list the modules whose name
or summary contain a given string such as "spam", type "modules spam".

help>

modules
keywords
symbols
topics
type

modules

help> modules

Please wait a moment while I gather a list of all available modules...

invalid distro: 'Ubuntu'
AptUrl apport_python_hook hmac sched
CommandNotFound apt html secrets
Crypto aptdaemon http select
DistUpgrade aptsources httplib2 selectors
LanguageSelector argparse idlelib shelve
NvidiaDetector array imaplib shlex
Onboard ast imghdr shutil
Quirks asynchat imp signal
UbuntuDrivers asyncio importlib site
UpdateManager asyncore inspect sitecustomize
__future__ atexit io six
_ast audioop ipaddress smtpd
_asyncio base64 itertools smtplib
_bisect bdb janitor sndhdr
_blake2 binascii json socket
_bootlocale binhex keyword socketserver
_bz2 bisect language_support_pkgs softwarecenter_aptd_plugins
_codecs builtins lib2to3 softwareproperties
_codecs_cn bytecode linecache speechd
_codecs_hk bz2 locale speechd_config
_codecs_iso2022 cProfile logging spwd
_codecs_jp cairo louis sqlite3
_codecs_kr calendar lsb_release sre_compile
_codecs_tw cgi lxml sre_constants
_collections cgitb lzma sre_parse
_collections_abc chardet macpath ssl
_compat_pickle checkbox_ng macurl2path stat
_compression checkbox_support mailbox statistics
_crypt chunk mailcap string
_csv cmath mako stringprep
_ctypes cmd markupsafe struct
_ctypes_test code marshal subprocess
_curses codecs math sunau
_curses_panel codeop mimetypes symbol
_datetime collections mmap symtable
_dbm colorsys modulefinder sys
_decimal compileall multiprocessing sysconfig
_dummy_thread concurrent netrc syslog
_elementtree configparser nis tabnanny
_functools contextlib nntplib tarfile
_hashlib copy ntpath telnetlib
_heapq copyreg nturl2path tempfile
_imp crypt numbers termios
_io csv oauthlib test
_json ctypes oneconf textwrap
_locale curl opcode this
_lsprof curses operator threading
_lzma datetime optparse time
_markupbase dbm orca timeit
_md5 dbus os tkinter
_multibytecodec deb822 ossaudiodev token
_multiprocessing debconf parser tokenize
_opcode debian pathlib trace
_operator debian_bundle pdb traceback
_osx_support decimal pickle tracemalloc
_pickle defer pickletools tty
_posixsubprocess difflib pipes turtle
_pydecimal dis piston_mini_client types
_pyio distutils pkg_resources typing
_random doctest pkgutil ufw
_sha1 dummy_threading plainbox unicodedata
_sha256 email platform unittest
_sha3 encodings plistlib uno
_sha512 enum poplib unohelper
_signal errno posix urllib
_sitebuiltins faulthandler posixpath urllib3
_socket fcntl pprint usbcreator
_sqlite3 feedparser problem_report uu
_sre feedparser_sgmllib3 profile uuid
_ssl filecmp pstats venv
_stat fileinput pty warnings
_string fnmatch pwd wave
_strptime formatter py_compile weakref
_struct fpectl pyatspi webbrowser
_symtable fractions pyclbr wsgiref
_sysconfigdata_m_linux_i386-linux-gnu friends pydoc xdg
_testbuffer ftplib pydoc_data xdiagnose
_testcapi functools pyexpat xdrlib
_testimportmultiple gc pygtkcompat xkit
_testmultiphase genericpath pyparsing xml
_thread getopt queue xmlrpc
_threading_local getpass quopri xxlimited
_tracemalloc gettext random xxsubtype
_warnings gi re zipapp
_weakref glob readline zipfile
_weakrefset gnome_sudoku reprlib zipimport
abc grp requests zlib
aifc gzip resource
antigravity hashlib rlcompleter
apport heapq runpy

Enter any module name to get more help. Or, type "modules spam" to search
for modules whose name or summary contain the string "spam".

Keywords

help> keywords

Here is a list of the Python keywords. Enter any keyword to get more help.

False def if raise
None del import return
True elif in try
and else is while
as except lambda with
assert finally nonlocal yield
break for not
class from or
continue global pass

symbols

help> symbols

Here is a list of the punctuation symbols which Python assigns special meaning
to. Enter any symbol to get more help.

!= *= << ^
" + <<= ^=
""" += <= _
% , <> __
%= - == `
& -= > b"
&= . >= b'
' ... >> j
''' / >>= r"
( // @ r'
) //= J |
* /= [ |=
** : \ ~
**= < ]

Tpoics

help> topics

Here is a list of available topics. Enter any topic name to get more help.

ASSERTION DELETION LOOPING SHIFTING
ASSIGNMENT DICTIONARIES MAPPINGMETHODS SLICINGS
ATTRIBUTEMETHODS DICTIONARYLITERALS MAPPINGS SPECIALATTRIBUTES
ATTRIBUTES DYNAMICFEATURES METHODS SPECIALIDENTIFIERS
AUGMENTEDASSIGNMENT ELLIPSIS MODULES SPECIALMETHODS
BASICMETHODS EXCEPTIONS NAMESPACES STRINGMETHODS
BINARY EXECUTION NONE STRINGS
BITWISE EXPRESSIONS NUMBERMETHODS SUBSCRIPTS
BOOLEAN FLOAT NUMBERS TRACEBACKS
CALLABLEMETHODS FORMATTING OBJECTS TRUTHVALUE
CALLS FRAMEOBJECTS OPERATORS TUPLELITERALS
CLASSES FRAMES PACKAGES TUPLES
CODEOBJECTS FUNCTIONS POWER TYPEOBJECTS
COMPARISON IDENTIFIERS PRECEDENCE TYPES
COMPLEX IMPORTING PRIVATENAMES UNARY
CONDITIONAL INTEGER RETURNING UNICODE
CONTEXTMANAGERS LISTLITERALS SCOPING
CONVERSIONS LISTS SEQUENCEMETHODS
DEBUGGING LITERALS SEQUENCES

help> type
Help on class type in module builtins:

class type(object)
| type(object_or_name, bases, dict)
| type(object) -> the object's type
| type(name, bases, dict) -> a new type
|
| Methods defined here:
|
| __call__(self, /, *args, **kwargs)
| Call self as a function.
|
| __delattr__(self, name, /)
| Implement delattr(self, name).
|
| __dir__(...)
| __dir__() -> list
| specialized __dir__ implementation for types
|
| __getattribute__(self, name, /)
| Return getattr(self, name).
|
| __init__(self, /, *args, **kwargs)
| Initialize self. See help(type(self)) for accurate signature.
|
| __instancecheck__(...)
| __instancecheck__() -> bool
| check if an object is an instance
|
| __new__(*args, **kwargs)
| Create and return a new object. See help(type) for accurate signature.
|
| __prepare__(...)
| __prepare__() -> dict
| used to create the namespace for the class statement
|
| __repr__(self, /)
| Return repr(self).
|
| __setattr__(self, name, value, /)
| Implement setattr(self, name, value).

Install Python3.6 on Ubuntu

sudo add-apt-repository ppa:jonathonf/python-3.6
sudo apt-get update
sudo apt-get install python3.6

reference
https://askubuntu.com/questions/865554/how-do-i-install-python-3-6-using-apt-get

Python view Byte Code for the given script

Python view Byte Code for the given script

Normal execution syntax
python file_name.py

For retrieving the Byte Code information the execution syntax is,
python -m dist file_name.py

which will display in a disassembler format (human readable format)

Example :

# simple.py

a=10

b=20

c=a+b
print(c)

#output

#cat bytecode.py


a=10
b=20
c=a+b
print(c)

#python3.6 bytecode.py

#python3.6 -m dis bytecode.py


  1           0 LOAD_CONST               0 (10)
              2 STORE_NAME               0 (a)

  2           4 LOAD_CONST               1 (20)
              6 STORE_NAME               1 (b)

  3           8 LOAD_NAME                0 (a)
             10 LOAD_NAME                1 (b)
             12 BINARY_ADD
             14 STORE_NAME               2 (c)

  4          16 LOAD_NAME                3 (print)
             18 LOAD_NAME                2 (c)
             20 CALL_FUNCTION            1
             22 POP_TOP
             24 LOAD_CONST               2 (None)
             26 RETURN_VALUE

Friday 3 November 2017

Python Microsoft Visual C++ 14.0 is required error while pip install

Python Microsoft Visual C++ 14.0 is required error while pip install

Error
-------

Collecting dist
Using cached dist-1.0.3.zip
Installing collected packages: dist
Running setup.py install for dist: started
Running setup.py install for dist: finished with status 'error'
Complete output from command C:\Python36-32\python.exe -u -c "import setuptools, tokenize;__file__='C:\\Users\\alps\\AppData\\Local\\Temp\\pycharm-packaging\\dist\\setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record C:\Users\alps\AppData\Local\Temp\pip-62o9v2z5-record\install-record.txt --single-version-externally-managed --compile:
running install
running build
running build_ext
building 'dist' extension
error: Microsoft Visual C++ 14.0 is required. Get it with "Microsoft Visual C++ Build Tools": http://landinghub.visualstudio.com/visual-cpp-build-tools

----------------------------------------

Command "C:\Python36-32\python.exe -u -c "import setuptools, tokenize;__file__='C:\\Users\\alps\\AppData\\Local\\Temp\\pycharm-packaging\\dist\\setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record C:\Users\alps\AppData\Local\Temp\pip-62o9v2z5-record\install-record.txt --single-version-externally-managed --compile" failed with error code 1 in C:\Users\alps\AppData\Local\Temp\pycharm-packaging\dist\

pytho 3.x required "Microsoft Visual C++ 14.0"

before that install dotnet 4.5.1 which will be the minimum required version to be available on the machine before executing MS visutal c++ 14.0
https://www.microsoft.com/en-in/download/details.aspx?id=40779
so post installing python dont forget to install the package which can be downloaded from
http://landinghub.visualstudio.com/visual-cpp-build-tools

post installation restart the machine to take effect the changes

How to create compiled files in python (py to pyc conversion)

How to create compiled files in python (py to pyc conversion)

This post explains about generating compiled files in python(py to pyc conversion).

The syntax is given as follows,

python -m py_compile file_name.py

where,
python is the executor command
-m is to represent the module
py_compile is the module to be called
file_name.py is the actual file which has to be compiled

This will create a output file like file_name.cpython.pyc

Thursday 2 March 2017

Python 3 While Loop

Python 3 While Loop

The below code block is an example for python while loop

'''While loops'''
a = 11
while a>10:
    a+=1

    print (a)
    break       # prints 12 and then breaks

Wednesday 1 March 2017

Python 3 Conditional Operators

Python 3 Conditional Operators

The explanation programs for conditional operators is as follows,

'''Conditional Operation'''

a = 100

if a == 100:
    print ("true")
else:
    print ("false")

# result is true
if a <50:
    print ("less than 50")
else:
    if a > 50:
        print ("greater than 50")

# result is greater than 50
if a < 50:
    print ("less than 50")
elif a>50:
    print ("greater than 50")
    
# result is greater than 50