If you want to execute some action for every element present in some sequence(it may be string or collection) then you should go for for loop.
for x in sequence: statements
Where sequence can be string or any collection. Statements will be executed for every element present in the sequence.
You can print characters present in the given string as follows,
s="Python" for x in s : print(x) Output P y t o n
You cannot empty for loops but if for some reason have a for loop without content then put a pass statement in the loop to avoid getting any error.
for x in [0, 1, 2]: pass
To iterate through a set of code a specified number of times you can use the range() function, The range() function returns a sequence of numbers starting from 0 (zero) by default and increments by 1 but ends at a specified number.
Using the range() function:
for x in range(6): print(x) Output 0 1 2 3 4 5
Note: range(6) is not the values of 0 to 6 but the values 0 to 5.
The range() function by default starting value from 0 (zero) however it is possible to specify the starting value by adding a parameter range(2, 6) which means values from 2 to 6 (but excluding 6):
for x in range(2, 6): print(x) Output 2 3 4 5
The range() function by defaults increment the sequence by 1 however it is possible to specify the increment value by adding a third parameter range(2, 30, 3) Increment the sequence with 3.
for x in range(2, 30, 3): print(x) Output 2 5 8 11 14 17 20 23 26 29
Else function in For Loop
Else keyword in a for loop is required to specifies a block of code to be executed when the loop is finished.
Print all numbers from 0 to 5 and print a message when the loop got ended,
for x in range(6): print(x) else: print("loop finished!") Output 0 1 2 3 4 5 loop finished!
Using break statement you can stop the loop before it has looped through all the items.
Exit the loop when x is 2,
Number = [1, 2, 3, 4, 5] for x in Number: print(x) if x == 2: break Output 1 2
Using continue statement you can stop the current iteration of the loop and continue with the next.
Here do not print 3,
Number = [1, 2, 3, 4, 5] for x in Number: if x == 3: continue print(x) Output 1 2 4 5
A nested loop is nothing but a loop inside another loop. The inner loop executes one time for each iteration of the outer loop. Here print each adjective for every fruit,
adj = ["red", "big", "tasty"] fruits = ["apple", "banana", "cherry"] for x in adj: for y in fruits: print(x, y) Output red apple red banana red cherry big apple big banana big cherry tasty apple tasty banana
Read Also : Differences between List and Tuple in Python