For statement

The syntax of the 'for' statement is

for variable in list:
    statements

Let's break down all the new words and what they mean:

• The for keyword:
  This is the starting point that tells Python you want to create a loop
• The variable part: This is a variable name you choose It temporarily holds each value from the list as the loop runs You can name it anything (following Python variable naming rules) Example: item, x, number, etc.
• The in keyword: It specifies that your variable will take values FROM the list/sequence Always comes between the variable and the list
• The list part: This is the sequence of items you want to loop over. Examples: [1, 2, 3], "hello", range(5)
• The colon ":": Marks the end of the for loop declaration Tells Python that the next line will contain the code to be repeated
• The statements part: These are the lines of code you want to repeat Must be indented (typically 4 spaces) Will be executed once for each item in the list

Continue

Let us practice what we learnt.

avengers=["iron man","spiderman","hulk","captain america","thor"]

for x in avengers:
    print(x)

In the above code, avengers is a listloop.

The loop will run 564 times.

The above program will print the name of the avengers one at a time. Changes the names, remove some super heroes, add some super heores and run the program. see how the loop perfroms.

With these two new concepts lets see how we can solve the largest number problem. The English code can be

1. Store numbers in a list.

2. Let us pick the first number. Let's call it as largest.

3. for every number in list do the below

4. if number is greater than largest

5. Make number as largest

   What steps 4 and 5 are doing is making sure that we always have the largest number in our hand. If the next number we pick is larger than the one in hand, we drop the one in our hand and keep the new number. If not, we continue to next number. Finally:

6. Print largest.

Continue

Now lets do the actual Python code with the correct syntax.

First step was: Store numbers in a list. Choose the correct approach in Python.

numbers=[5,1,3]number1=5,number2=1, number3=3

numbers=[5,1,3,8,4]
largest=numbers[0]
for number in numbers:
    if number > largest:
        largest=number
    

print(largest)

Notice how close the Python program is to our general language. You just need to be careful with the indentation and the syntax.

Let's do a quick revision. In Python language we have learnt:

1. Assignment
2. Conditionals
3. Loops

With these three constructs you can write almost any program you want. Programming is really so simple. Just these 3 statements and you can make the computer do whatever you want.

Let's see if you can solve the following problem by yourself.

Problem: Take 10 numbers in a list. Take a number you have to search in another variable. Search for the second number in the list. If the number is found, print found. If not, print not found.

Discuss with your parents or friends. Take your time. Work slowly one step at a time. This is one of the most common problem in computer science. So if you get this you have done a great job. Once you are done, let's go to the next chapter.