Python Route-basics-8 loops

There are two loops in Python, namely A For loop and a while loop, which iterate over the data of the sequence:

For loop

The For loop iterates through each element of a list, tuple, or string, for example:

names = ["zhangcong""lisanjiang" "Pangzhiguo  "] for in names:    print  name # Execution Results Zhangconglisanjiangpangzhiguo

So for the X in ... A loop is a statement that assigns each element to a variable x and then executes the indentation.
Example: You need to figure out 1-10

numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, ten= 0 for in numbers:    + = i    #< /c7> sum + = i   = =   sum = sum + i  it's just shorthand. print  sum#  Execution Result 55

The list can also be replaced with a range, and the range () function can generate an integer sequence, such as a range (5) that generates a sequence that is less than 5 of the integer starting at 0:

sum =0 forIinchRange (1, 11): Sum+=IPrintsum#Execution Results55that's what the authorities are explaining. Range (...) Range (stop)-List of integers range (start, stop[, step])-List of integers Return a list containing an arithmetic progression of integers. #returns a list of integers that contain a arithmetic progression. Range (I, j) returns [I, I+1, i+2, ..., j-1];    Start (!) defaults to 0. When step isGiven, it specifies the increment (ordecrement). For example, range (4) returns [0, 1, 2, 3]. The end point isomitted! These is exactly the valid indices forA list of 4 elements.

While Loop

While loop: As long as the conditions on the cycle, the general use of the dead loop will be used, such as we want to calculate the sum of all the odd within 100, can be implemented with a while loop:

# the loop internal variable n is continuously self-reducing until it becomes 1, and the while condition is no longer satisfied, and the loop exits sum == round while n > 0:    = sum +  n     = n-2print sum

Break

Break: Jump out of the current loop, end of loop
Example: Print 1-100, when I > 50 exits the Loop

i = 1 while True:        if i >:        breakPrint  i    + = 1 output result:12345678 ... 474849

Continue

Continue: Jump out of this loop for the next cycle
For example: printing 1-10, but not including 5

 for  in range    :if i = = 5:        continue    print  i  #  execution Results 1234678910

Python Route-basics-8 loops