Stupid methodology Python,lesson 32-lesson 34

Exercise 32

Code

the_count = [1, 2, 3, 4, 5]fruits = [' apples ',  ' oranges ',  ' Pears ',  ' apricots ']change = [1,  ' pennies ', 2,  "dimes ', 3,  ' quarters ']#  this first kind of for-loop goes through a listfor number  in the_count:    print  "this is count %d"  %  Number # same as abovefor fruit in fruits:    print   "a fruit of type: %s"  % fruit     # also  we can go through mixed lists too# notice we have to  use %r since we don ' T know what ' s in it for i in  change:    print  "I got %r"  % i # we can  also build lists, first start with an empty one elements = []# then use  the range function to do 0 to 5 countsfor i in  Range (0,6):    print  "Adding %d to the list."  % i     # append is a function that lists  understand     elements.append (i)      # now  we can print them out toofor i in elements:     print  "element was: %d"  % i

Output

Notes:

①range (start,end) returns an integer sequence, ranging from start to end-1

>>> Range (0.6) [0, 1, 2, 3, 4, 5]

②for...in ... Iterative loops apply to sequence types such as strings, lists, and so on

③ sequences can be connected by a plus sign to form a new sequence

>>> elements = []>>> elements + range (0,6) [0, 1, 2, 3, 4, 5]

Exercise 33

Code

i = 0numbers = []while i < 6:print "at the top I am%d"% i numbers.append (i) i = i + 1 print "Numbe RS Now: ", numbers print" At the bottom I was%d "% i print" The numbers: "For num in Numbers:print num

Output

Notes:

①while determines whether the loop continues by checking the true and false of the Boolean expression. Unless necessary, to minimize the use of while-loop, in most cases for-loop is a better choice; use While-loop when checking for changes in Boolean expressions to ensure that they eventually become false unless you want an infinite loop

② Plus points exercise a code rewrite

Code

i = 0numbers = []def numbers_list (x): Global numbers, I and I < X:print "at the top I am%d"% i          Numbers.append (i) i = i + 1 print "Numbers now:", numbers print "At the bottom I was%d"% i Numbers_list (7) print "The numbers:" For num in Numbers:print num

Output

PS: The function should pay attention to the problem of local variables and global variables.

③ Plus points exercise two code rewriting

Code

i = 0numbers = []def numbers_list (x, y): global numbers, I and I < X:print "at the top I am%d"% i Numbers.append (i) i = i + y print "numbers now:", numbers print "At the bottom I was%d" % i numbers_list (7, 3) print "The numbers:" For num in Numbers:print num

Output

Exercise 34

This section has no code, the main practice list of the slice, ordinal and cardinality problems

Practice:

The animal at 1 are the 2nd animal and is a python. The 3rd animal is at 2 and is a peocock. The 1st animal are at 0 and are a bear. The animal at 3 are the 4th animal and is a kanaroo. The 5th animal is at 4 and is a whale. The animal at 2 are the 3rd animal and is a peocock. The 6th animal is at 5 and is a platypus. The animal at 4 are the 5th and is a whale.

Stupid methodology Python,lesson 32-lesson