Python Programming Syntax

A quick reference for python installation, syntax and etc.

Installation

apt-get install python3
apt-get install python3-pip python3-wheel

Syntax

if

if expression:
        print "True"
    elif expression:
        print "False"
    
else:
 
        print "False"

multi line

total = item_one + \

        item_two + \
        item_three
 
days = ['Monday', 'Tuesday', 'Wednesday',

        'Thursday', 'Friday']
```

Statements contained within the [], {}, or () brackets do not need to use the line continuation character.

## print

print ( 'Key is : {}  -  {}'.format(key, servername ))
```

## while

def ask_ok(prompt, retries=4, reminder='Please try again!'):
    
    while True:
        
        ok = input(prompt)
        
        if ok in ('y', 'ye', 'yes'):
            
            return True
        
        if ok in ('n', 'no', 'nop', 'nope'):
            
            return False
        
        retries = retries - 1
        
        if retries < 0:
            
            raise ValueError('invalid user response')
        
        print(reminder)

```

## dictionary declaration

ansible_groups                 =        dict()
    if key in ansible_groups:
        ansible_groups[key].append(servername)
    else:
        ansible_groups[key]        =        [servername]

```

## looping

for key, value in sorted(ansible_groups.items()):
        print (key)
        for servername in value:
            print ( "---", servername )
        print ("")

    for index, value in enumerate(groupsplit):
        print (index)

```

## string functions

split
        group_split = key.split('|')
    lower
        str.lower()
        str.rsplit("_",3)

    "1_2_3_4_5".rsplit("_",1) ==> ['1_2_3_4', '5']
    "1_2_3_4_5".rsplit("_",2) ==> ['1_2_3, '4', '5']
    "1_2_3_4_5".rsplit("_",3) ==> ['1_2, '3', '4', '5']


```