sgouda0412

def timeit(function):
    '''Decorator used for debugging. Prints the call and how long it took.'''
    def timed(*args, **kwargs):
        ts = time.time()
        result = function(*args, **kwargs)
        te = time.time()
        print("{0} ({1}, {2}) {3:.2} sec"
              .format(function.__name__, args, kwargs, te - ts))

sgouda0412

import re
print(re.match(r'bc', 'abc'))
print(re.match(r'abc', 'abc'))
print(re.search(r'bc', 'abc'))
print(re.search(r'^bc', 'abc'))
print(re.search(r'^ab$', 'abc'))
print(re.search(r'^abc$', 'abc'))
print(re.search(r'a?bc', 'bc'))
print(re.search(r'a?bc', 'abc'))
print(re.search(r'a?bc', 'aabc'))

sgouda0412

Bash Scripting Cheatsheet

---

References

1. http://www.tldp.org/LDP/Bash-Beginners-Guide/html/index.html (Beginner)
2. http://www.tldp.org/LDP/abs/html/index.html (Advanced)
3. https://gist.github.com/LeCoupa/122b12050f5fb267e75f (Cheatsheet)

    ### 0. Special Characters (more info: http://tldp.org/LDP/abs/html/special-chars.html)
    # This is a comment

sgouda0412

vs Questions

---

1. http://stackoverflow.com/questions/804115 (rebase vs merge).
2. https://www.atlassian.com/git/tutorials/merging-vs-rebasing (rebase vs merge)
3. https://www.atlassian.com/git/tutorials/undoing-changes/ (reset vs checkout vs revert)
4. http://stackoverflow.com/questions/2221658 (HEAD^ vs HEAD~) (See git rev-parse)
5. http://stackoverflow.com/questions/292357 (pull vs fetch)
6. http://stackoverflow.com/questions/39651 (stash vs branch)
7. http://stackoverflow.com/questions/8358035 (reset vs checkout vs revert)

sgouda0412

#!/bin/bash

# Retries a command on failure.
# $1 - the max number of attempts
# $2... - the command to run
retry() {
    local -r -i max_attempts="$1"; shift
    local -r cmd="$@"
    local -i attempt_num=1

sgouda0412

# https://github.com/kennethreitz/requests/blob/master/requests/exceptions.py
class RequestException(IOError):
    """There was an ambiguous exception that occurred while handling your
    request.
    """

    def __init__(self, *args, **kwargs):
        """Initialize RequestException with `request` and `response` objects."""
        response = kwargs.pop('response', None)
        self.response = response

sgouda0412

# Count total EBS based storage in AWS
aws ec2 describe-volumes | jq "[.Volumes[].Size] | add"
# Count total EBS storage with a tag filter
aws ec2 describe-volumes --filters "Name=tag:Name,Values=CloudEndure Volume qjenc" | jq "[.Volumes[].Size] | add"
# Describe instances concisely
aws ec2 describe-instances | jq '[.Reservations | .[] | .Instances | .[] | {InstanceId: .InstanceId, State: .State, SubnetId: .SubnetId, VpcId: .VpcId, Name: (.Tags[]|select(.Key=="Name")|.Value)}]'
# Wait until $instance_id is running and then immediately stop it again
aws ec2 wait instance-running --instance-id $instance_id && aws ec2 stop-instances --instance-id $instance_id

# Get 10th instance in the account

sgouda0412

# adding and committing
git add -A                        # stages All
git add .                         # stages new and modified, without deleted
git add -u                        # stages modified and deleted, without new
git commit --amend                # Add staged changes to previous commit. Do not use if commit has been pushed.
git commit --amend --no-edit      # Do so without having to edit the commit message.

# remotes - pushing, pulling, and tracking
git fetch                         # gets remote objects and refs. Needed if new branches were added on the remote.
git remote -v                     # Lists all remotes (verbose)

sgouda0412

# Full path to file
os.path.join(os.path.dirname(os.path.realpath(__file__)), 'backups', 'file.zip')


def full_path(*args):
  """ full_path('dir', 'folder', 'file.txt') """
  return os.path.join(os.path.dirname(os.path.realpath(__file__)), *args)


def full_path(filepath, *args):

sgouda0412

/* 
	1. Using unicode symbol in string characters
	Use “\u” followed by the hexadecimal (base 16) code for the character in the Unicode tables.
	Unicode tables: http://www.unicode.org/charts/ 
        
    2. You can get the number corresponding to any character by using the ord() function and you can get the character corresponding to any number with the chr() function.
    >>> '\u011f' -> 'ğ' // 16-bit hex ('\uxxxx')
    >>> "\U00016FE1" -> '𖿡' // 32-bit hex ('\Uxxxxxxxx')
    >>> ord('ğ') -> 287
    >>> chr(287) -> 'ğ'