The Road to python-Basics 2

10. If else process judgment

Example 1:

Import getpass # refers to the module getpass _ username = "kk" _ password = "123456" username = input ("username:") password = getpass.getpass ("password") # getpass function is to make the password not directly displayed in plaintext if _ username = = username and _ password = = password: print ("Welcome user {name} login..." .format (name = username)) # print ("Welcome user% s login..."% username) else: print ("error")

Note: indent function: subcode needs to be indented

Example 2:

# guess age age_of_oldboy = 65guess_age = int (input ("guess age:") if guess_age = = age_of_oldboy: print ("Yes, you got it.") elif guess_age > age_of_oldboy: print ("No,think bigger!") else: print ("No,think smaller!")

11. While cycle

Example 1:

# endless loop count = 0while True: print ("count", count) count = count + 1

Example 2:

Age_of_oldboy = 65 count = 0 # set count while count

< 3:#如果小于3次时循环执行 #if count == 3: #break guess_age = int(input("guess age:")) if guess_age == age_of_oldboy: print("Yes, you got it.") break elif guess_age >

Age_of_oldboy: print ("No, think bigger!") Else: print ("No,think smaller!") Count + = 1else: print ("Funk off")

Example 3:

# cycle to guess the age, and the end prompt whether to continue guessing

Age_of_oldboy = 65count = 0while count

< 3:# if count == 3:# break guess_age = int(input("guess age:")) if guess_age == age_of_oldboy: print("Yes, you got it.") break elif guess_age >

Age_of_oldboy: print ("No, think bigger!") Else: print ("No,think smaller!") Count + = 1 if count = = 3 if count # guessed three times before asking the user whether to continue guessing coutine_confim = input ("do you want to keep guessing?:") if coutine_confim! = "n": count = 0#else:# this does not need # print ("Funk off")

Note:

Continue: jump out of this cycle and continue to the next cycle

Break: end the entire cycle

12. For cycle

Example 1:

# for loop for i in range (10): print ("loop", I)

Answer: C:\ Users\ Documents\ python > python learn01.pyloop 0loop 1loop 2loop 3loop 4loop 5loop 6loop 7loop 8loop 9

Example 2:

# cyclic age guessing

Age_of_oldboy = 65for i in range (3): guess_age = int (input ("guess age:")) if guess_age = = age_of_oldboy: print ("Yes, you got it.") Break elif guess_age > age_of_oldboy: print ("No, think bigger!") Else: print ("No,think smaller!") else: print ("Funk off")

Example 3:

For i in range (0Jing 10jue 2): print ("loop", I)

Examples 4:

# the big loop I executes once, and the small loop executes for i in range (10): print ('-', I) for j in range (10): print (j) if j > 5. If the small loop is greater than 5, stop break