If you are here, it means you are going to be a coder soon. You will solve real-world computer problems, make your own programs, and a lot more. Yeah, sounds good!

Now let's talk about '**for**'. It is also a loop like 'while'. Let's see how it works.

- Python 2
- Python 3

```
marks = [78,98,50,37,45]
for m in marks:
print(m)
```

Just this and it's done. Let me explain you the code.

`for m in marks`

→ 'm' is a variable which will go to every element in the list 'marks' and will take its value.

So, in the first iteration, *m* will be the 1^{st} element of the list. In the second iteration, *m* will be the 2^{nd} element of the list an so on.

As you have seen above, in the first iteration the value of *m* is 78, in the second iteration, its 98, then 50 and so on.

#### Example of the sum of marks

- Python 2
- Python 3

```
marks = [78,98,50,37,45]
sum = 0
for m in marks:
sum = sum+m
print(sum)
```

You must have got the code. If not, then let me explain a bit.

`sum = 0`

→ We are taking any variable and assigning it an initial value of 0.

**In the 1 ^{st} iteration**

*m*is 78. So,

`sum+m`

is `0+78`

. Now, the value of *sum*is 78

**In the 2**

^{nd}iteration*m*is 98. So,

`sum+m`

is `78+98`

. Now, the value of the *sum*is 176.

And similarly at last, sum is 308.

**for**loop on tuples and strings. Try it yourself.

Do You Know ? | ||

Table of 12 | Add | And you get table of 13 |
---|---|---|

12 | +1 | 13 |

24 | +2 | 26 |

36 | +3 | 39 |

48 | +4 | 52 |

60 | +5 | 65 |

72 | +6 | 78 |

84 | +7 | 91 |

96 | +8 | 104 |

108 | +9 | 117 |

120 | +10 | 130 |

So, let's do it with the help of for loop.

- Python 2
- Python 3

```
table_12 = [12,24,36,48,60,72,84,96,108,120]
table_13 = []
z = 1
for i in table_12:
table_13.append(i+z) #using append to add an element in front of list
z = z+1
print(table_13)
```

`z = 1`

→ We have to add 1,2,3... respectively to each element. And that's what we are doing. Add 1 then increase z by 1 for the next turn (z = z+1).

`table_13.append()`

→ 'append()' is a function of list which adds an element in front of a list. So, (i+z) will add (12+1),(12+2),...(12+10) in their respective turns in the list.

By writing codes, your mathematics is going to be fun.