# 1-4 Basics of Python

Type() is used to identify a type of a variable.

### Types of variables ###
1. Int
```
a = 5
type(a)
```
```
int
```

2. Float
```
b = 5.0
type(b)
```
```
float
```

3. Str
```
c = 'Hello'
type(c)
```
```
str
```

4. List
```
list1 = [1, 2, 3, 4, 5]
list2 = ['a', 'b', 'c', 'd', 'e']
print(type(list1))
print(type(list2))
```
```
<class 'list'>
<class 'list'>
```

#### variables should be in the square brackets. ####

> Indexing: 
used to select a variable in a specific order. The order number starts with 0.
```
list = ['a', 'k', 'j', 'b', 's', 'v', '!']
```
```
list[0]
```
```
'a'
```

> Append: 
used to add another variable to the list.
```
list_1 = [1, 2, 3, 4, 5]
```
```
list_1.append(155)
list_1
```
```
[1, 2, 3, 4, 5, 155]
```

> Extend: 
used to merge one list with another list.
```
list_2 = ['a', 'b', 'c']
```
```
list_1.extend(list_2)
print(list_1)
```
```
[1, 2, 3, 4, 5, 155, 'a', 'b', 'c']
```