Python Cheatsheet
Python sys Variables
| variable | meaning |
|---|
| argv | Command line args |
| builtin_module_names | Linked C modules |
| byteorder | Native byte order |
| check_interval | Signal check frequency |
| exec_prefix | Root directory |
| executable | Name of executable |
| exitfunc | Exit function name |
| modules | Loaded modules |
| path | Search path |
| platform | Current platform |
| stdin, stdout, stderr | File objects for I/O |
| version_info | Python version info |
| winver | Version number |
Python sys.argv
sys.argv for the command:
python foo.py bar -c qux --h
| sys.argv | part of the command |
|---|
| sys.argv[0] | foo.py |
| sys.argv[1] | bar |
| sys.argv[2] | -c |
| sys.argv[3] | qux |
| sys.argv[4] | –h |
Python os Variables
| OS Variable | meaning |
|---|
| altsep | Alternative sep |
| curdir | Current dir string |
| defpath | Default search path |
| devnull | Path of null device |
| extsep | Extension separator |
| linesep | Line separator |
| name | Name of OS |
| pardir | Parent dir string |
| pathsep | Patch separator |
| sep | Path separator |
Python Class Special Methods
__new__(cls)__lt__(self, other)__init__(self, args)__le__(self, other)__del__(self)__gt__(self, other)__repr__(self)__ge__(self, other)__str__(self)__eq__(self, other)__cmp__(self, other)__ne__(self, other)__index__(self)__nonzero__(self)__hash__(self)__getattr__(self, name)__getattribute__(self, name)__setattr__(self, name, attr)__delattr__(self, name)__call__(self, args, kwargs)
Python List Methods
- append(item)
- pop(position)
- count(item)
- remove(item)
- extend(list)
- reverse()
- index(item)
- sort()
- insert(position, item)
Python String Methods
- capitalize() : for 8-bit strings
- lstrip()
- center(width)
- partition(sep)
- count(sub, start, end)
- replace(old, new)
- decode()
- rfind(sub, start ,end)
- encode()
- rindex(sub, start, end)
- endswith(sub)
- rjust(width)
- expandtabs()
- rpartition(sep)
- find(sub, start, end)
- rsplit(sep)
- index(sub, start, end)
- rstrip()
- isalnum() : for 8-bit strings
- split(sep)
- isalpha() : for 8-bit strings
- splitlines()
- isdigit() : for 8-bit strings
- startswith(sub)
- islower() : for 8-bit strings
- strip()
- isspace() : for 8-bit strings
- swapcase() : for 8-bit strings
- istitle() : for 8-bit strings
- title() : for 8-bit strings
- isupper() : for 8-bit strings
- translate(table)
- join()
- upper() : for 8-bit strings
- ljust(width)
- zfill(width)
- lower() : for 8-bit strings
Python File Methods
- close()
- readlines(size)
- flush()
- seek(offset)
- fileno()
- tell()
- isatty()
- truncate(size)
- next()
- write(string)
- read(size)
- writelines(list)
- readline(size)
Python Indexes and Slices
Indexes and Slices of a=[0,1,2,3,4,5].
| slices | meaning |
|---|
len(a) | 6 |
a[0] | 0 |
a[5] | 5 |
a[-1] | 5 |
a[-2] | 4 |
a[1:] | [1,2,3,4,5] |
a[:5] | [0,1,2,3,4] |
a[:-2] | [0,1,2,3] |
a[1:3] | [1,2] |
a[1:-1] | [1,2,3,4] |
b=a[:] | Shallow copy of a |
Python Datetime Methods
- today()
- fromordinal(ordinal)
- now(timezoneinfo)
- combine(date, time)
- utcnow()
- strptime(date, format)
- fromtimestamp(timestamp)
- utcfromtimestamp(timestamp)
Python Time Methods
- replace()
- utcoffset()
- isoformat()
- dst()
__str__()- tzname()
- strftime(format)
| Format | Meaning |
|---|
| %a | Abbreviated weekday (Sun) |
| %A | Weekday (Sunday) |
| %b | Abbreviated month name (Jan) |
| %B | Month name (January) |
| %c | Date and time |
| %d | Day (leading zeros) (01 to 31) |
| %H | 24 hour (leading zeros) (00 to 23) |
| %I | 12 hour (leading zeros) (01 to 12) |
| %j | Day of year (001 to 366) |
| %m | Month (01 to 12) |
| %M | Minute (00 to 59) |
| %p | AM or PM |
| %S | Second (00 to 61) |
| %U | Week number (00 to 53) |
| %w | Weekday (0 to 6) |
| %W | Week number (00 to 53) |
| %x | Date |
| %X | Time |
| %y | Year without century (00 to 99) |
| %Y | Year (2008) |
| %Z | Time zone (GMT) |
| %% | A literal “%” character (%) |
That’s it. Hope it helps.