Python Cheat Sheet Part - 3
Tags: beginners, programming, tutorial, python
Published: 2022-05-03 19:22:29

**Dictionaries**
The dictionary is an unordered set of comma-separated key:value pairs, within {}, with the requirement that within a dictionary, no two keys can be the same.

**Dictionary**

```
<dictionary-name> = {<key>: value, <key>: value ...}
```
**Adding Element to a dictionary**
By this method, one can add new elements to the dictionary

```
<dictionary>[<key>] = <value>
```
**Updating Element in a dictionary**
If a specified key already exists, then its value will get updated

```
<dictionary>[<key>] = <value>
```
**Deleting an element from a dictionary**
del keyword is used to delete a specified key:value pair from the dictionary as follows:

```
del <dictionary>[<key>]
```
**Dictionary Functions & Methods**
Below are some of the methods of dictionaries

**len() method**
It returns the length of the dictionary, i.e., the count of elements (key: value pairs) in the dictionary

```
len(dictionary)
```
**clear() method**
Removes all the elements from the dictionary

```
dictionary.clear()
```
**get() method
**Returns the value of the specified key

```
dictionary.get(keyname)
```
**items() method**
Returns a list containing a tuple for each key-value pair

```
dictionary.items()
```
**keys() method**
Returns a list containing the dictionary's keys

```
dictionary.keys()
```
**values() method**
Returns a list of all the values in the dictionary

```
dictionary.values()
```
**update() method**
Updates the dictionary with the specified key-value pairs

```
dictionary.update(iterable)
```


**Conditional Statements**
The if, elif and else statements are the conditional statements in Python, and these implement selection constructs (decision constructs).

**if Statement**

```
if(conditional expression):
    statements
```
**if-else Statement**

```
if(conditional expression):
    statements
else:
    statements
```
**if-elif Statement**

```
if (conditional expression):
    statements
elif (conditional expression):
    statements
else:
    statements
```
**Nested if-else Statement**

```
if (conditional expression):
    if (conditional expression):
        statements
    else:
        statements
else:
    statements
```

**Loops in Python**
A loop or iteration statement repeatedly executes a statement, known as the loop body, until the controlling expression is false (0).

**For Loop**
The for loop of Python is designed to process the items of any sequence, such as a list or a string, one by one.

```
for <variable> in <sequence>:
    statements_to_repeat
```
**While Loop**
A while loop is a conditional loop that will repeat the instructions within itself as long as a conditional remains true.

```
while <logical-expression>:
    loop-body
```
**Break Statement**
The break statement enables a program to skip over a part of the code. A break statement terminates the very loop it lies within.

```
for <var> in <sequence>:
    statement1
    if <condition>:
        break
    statement2
statement_after_loop
```
**Continue Statement**
The continue statement skips the rest of the loop statements and causes the next iteration to occur.

```
for <var> in <sequence>:
    statement1
    if <condition> :
        continue
    statement2
    statement3
    statement4
```
**Functions**
A function is a block of code that performs a specific task. You can pass parameters into a function. It helps us to make our code more organized and manageable.

```
Function Definition
def my_function(parameters):
    pass #statements
```

[Python cheat sheet part-1](https://dev.to/sandeepk27/python-cheat-sheet-for-beginners-part-1-5baj)


[Python cheat sheet part-2](https://dev.to/sandeepk27/python-cheat-sheet-part-2-5cc3)


[Top Websites to learn Python](https://dev.to/sandeepk27/top-websites-to-learn-python-for-free-1j1l)


[How to install python in windows 10](https://dev.to/sandeepk27/how-to-install-python-310-2dik)


[Best IDE's for Python](https://dev.to/sandeepk27/best-ides-for-python-362k)