46 Simple Python Exercises 16-22题

Posted 2020-09-05

会贴出原题和答案，答案不是最优的，也反映了我的学习过程，如果有时间会更新优化的代码。


Write a function filter_long_words() that takes a list of words and an integer n and returns the list of words that are longer than n.



#Write a function filter_long_words() that takes a list of words
# and an integer n and returns the list of words that are longer than n.
def filter_long_words(list,n):
    words = []
    for word in list:
        if len(word)>n:
            words.append(word)
    return (words)
print(filter_long_words([‘abc‘,‘long‘,‘filter‘,‘return‘],4))

 



Write a version of a palindrome recognizer that also accepts phrase palindromes such as "Go hang a salami I‘m a lasagna hog.", "Was it a rat I saw?", "Step on no pets", "Sit on a potato pan, Otis", "Lisa Bonet ate no basil", "Satan, oscillate my metallic sonatas", "I roamed under it as a tired nude Maori", "Rise to vote sir", or the exclamation "Dammit, I‘m mad!". Note that punctuation, capitalization, and spacing are usually ignored.



#Write a version of a palindrome recognizer that also accepts phrase palindromes
# such as "Go hang a salami I‘m a lasagna hog.", "Was it a rat I saw?", "Step on no pets",
# "Sit on a potato pan, Otis", "Lisa Bonet ate no basil", "Satan, oscillate my metallic sonatas",
# "I roamed under it as a tired nude Maori", "Rise to vote sir", or the exclamation "Dammit, I‘m mad!".
# Note that punctuation, capitalization, and spacing are usually ignored.
import re
def palindrome_recognizer(words):
    album = []
    word=re.sub(‘[^a-zA-Z]‘,‘‘,words).lower()
    for str in (word):
        album.insert(0, str)
    if word==(‘‘.join(album)):
        return True
    else:
        return  False
a=palindrome_recognizer("I am testing")
print(a)
b=palindrome_recognizer("Go hang a salami I‘m a lasagna hog.")
print(b)
c=palindrome_recognizer("Was it a rat I saw?")
print(c)
d=palindrome_recognizer("Sit on a potato pan, Otis")
print(d)
e=palindrome_recognizer("Dammit, I‘m mad!")
print(e)

 



A pangram is a sentence that contains all the letters of the English alphabet at least once, for example: The quick brown fox jumps over the lazy dog. Your task here is to write a function to check a sentence to see if it is a pangram or not.



#A pangram is a sentence that contains all the letters of the English alphabet at least once,
# for example: The quick brown fox jumps over the lazy dog.
# Your task here is to write a function to check a sentence to see if it is a pangram or not.
import re
def pangram_check(sentence):
    alphabets=[‘a‘, ‘b‘,‘c‘,‘d‘,‘e‘,‘f‘,‘g‘,‘h‘,‘i‘,‘j‘,‘k‘,‘l‘,‘m‘,‘n‘,‘o‘,‘p‘,‘q‘,‘r‘,‘s‘,‘t‘,‘u‘,‘v‘,‘w‘,‘x‘,‘y‘,‘z‘]
    words = re.sub(‘[^a-zA-Z]‘, ‘‘, sentence).lower()
    i=0
    for alphabet in alphabets:
        if alphabet in words:
            i=i+1
    if i==26:
        return  True
    else:
        return False
a="The quick brown fox jumps over the lazy dog."
print(pangram_check(a))
b="The quick brown fox jumps over the lazy cat."
print(pangram_check(b))

 



"99 Bottles of Beer" is a traditional song in the United States and Canada. It is popular to sing on long trips, as it has a very repetitive format which is easy to memorize, and can take a long time to sing. The song‘s simple lyrics are as follows:



99 bottles of beer on the wall, 99 bottles of beer.


Take one down, pass it around, 98 bottles of beer on the wall.


The same verse is repeated, each time with one fewer bottle. The song is completed when the singer or singers reach zero.


Your task here is write a Python program capable of generating all the verses of the song.


#"99 Bottles of Beer" is a traditional song in the United States and Canada.
# It is popular to sing on long trips,
# as it has a very repetitive format which is easy to memorize,
# and can take a long time to sing. The song‘s simple lyrics are as follows:
# 99 bottles of beer on the wall, 99 bottles of beer.
#Take one down, pass it around, 98 bottles of beer on the wall.
#The same verse is repeated, each time with one fewer bottle.
#  The song is completed when the singer or singers reach zero.
#Your task here is write a Python program capable of generating all the verses of the song.
def Bottles_of_Beer(n):
    bottles=n
    while  bottles >0:
        print(‘{0} bottles of beer on the wall,{0} bottles of beer‘.format(bottles))
        print(‘Take one down,pass it around,{} bottles of beer on the wall‘.format(bottles-1))
        bottles=bottles-1
Bottles_of_Beer(3)

 




Represent a small bilingual lexicon as a Python dictionary in the following fashion {"merry":"god", "christmas":"jul", "and":"och", "happy":gott", "new":"nytt", "year":"?r"} and use it to translate your Christmas cards from English into Swedish. That is, write a function translate() that takes a list of English words and returns a list of Swedish words.



#Represent a small bilingual lexicon as a Python dictionary in the following fashion
# {"merry":"god", "christmas":"jul", "and":"och", "happy":gott", "new":"nytt", "year":"ar"}
# and use it to translate your Christmas cards from English into Swedish.
# That is, write a function translate() that takes a list of English words
# and returns a list of Swedish words.
def translate(English_words):
    dictionary={"merry":"god","christmas":"jul","and":"och","happy":"gott","new":"nytt","year":"ar"}
    Swedish=[]
    for words in English_words.lower().split():
        if words in dictionary:
            Swedish.append(dictionary[words])
    return(‘ ‘.join(Swedish))
a=‘Merry christmas‘
print(translate(a))
b=‘HAPPY NEW YEAR‘
print(translate(b))
c=‘Merry Christmas and Happy New Year‘
print(translate(c))

 



Write a function char_freq() that takes a string and builds a frequency listing of the characters contained in it. Represent the frequency listing as a Python dictionary. Try it with something like char_freq("abbabcbdbabdbdbabababcbcbab").



#Write a function char_freq() that takes a string and builds a frequency
# listing of the characters contained in it.
# Represent the frequency listing as a Python dictionary.
#  Try it with something like char_freq("abbabcbdbabdbdbabababcbcbab").
def char_freq(char):
    alphabets=set(char)
    for alphabet in alphabets:
        counts_dict = {alphabet:char.count(alphabet)}
        print (‘{}:{}‘.format(alphabet,counts_dict[alphabet]))
a="abbabcbdbabdbdbabababcbcbab"
char_freq(a)

 



In cryptography, a Caesar cipher is a very simple encryption techniques in which each letter in the plain text is replaced by a letter some fixed number of positions down the alphabet. For example, with a shift of 3, A would be replaced by D, B would become E, and so on. The method is named after Julius Caesar, who used it to communicate with his generals. ROT-13 ("rotate by 13 places") is a widely used example of a Caesar cipher where the shift is 13. In Python, the key for ROT-13 may be represented by means of the following dictionary:



key = {‘a‘:‘n‘, ‘b‘:‘o‘, ‘c‘:‘p‘, ‘d‘:‘q‘, ‘e‘:‘r‘, ‘f‘:‘s‘, ‘g‘:‘t‘, ‘h‘:‘u‘, ‘i‘:‘v‘, ‘j‘:‘w‘, ‘k‘:‘x‘, ‘l‘:‘y‘, ‘m‘:‘z‘, ‘n‘:‘a‘, ‘o‘:‘b‘, ‘p‘:‘c‘, ‘q‘:‘d‘, ‘r‘:‘e‘, ‘s‘:‘f‘, ‘t‘:‘g‘, ‘u‘:‘h‘, ‘v‘:‘i‘, ‘w‘:‘j‘, ‘x‘:‘k‘, ‘y‘:‘l‘, ‘z‘:‘m‘, ‘A‘:‘N‘, ‘B‘:‘O‘, ‘C‘:‘P‘, ‘D‘:‘Q‘, ‘E‘:‘R‘, ‘F‘:‘S‘, ‘G‘:‘T‘, ‘H‘:‘U‘, ‘I‘:‘V‘, ‘J‘:‘W‘, ‘K‘:‘X‘, ‘L‘:‘Y‘, ‘M‘:‘Z‘, ‘N‘:‘A‘, ‘O‘:‘B‘, ‘P‘:‘C‘, ‘Q‘:‘D‘, ‘R‘:‘E‘, ‘S‘:‘F‘, ‘T‘:‘G‘, ‘U‘:‘H‘, ‘V‘:‘I‘, ‘W‘:‘J‘, ‘X‘:‘K‘, ‘Y‘:‘L‘, ‘Z‘:‘M‘}


Your task in this exercise is to implement an encoder/decoder of ROT-13. Once you‘re done, you will be able to read the following secret message:


Pnrfne pvcure? V zhpu cersre Pnrfne fnynq!


Note that since English has 26 characters, your ROT-13 program will be able to both encode and decode texts written in English.


‘‘‘
In cryptography, a Caesar cipher is a very simple encryption techniques
in which each letter in the plain text is replaced by a letter
some fixed number of positions down the alphabet. For example,
with a shift of 3, A would be replaced by D, B would become E, and so on.
The method is named after Julius Caesar, who used it to communicate with his generals.
ROT-13 ("rotate by 13 places") is a widely used example of a Caesar cipher
where the shift is 13. In Python, the key for ROT-13 may be represented
by means of the following dictionary:
key = {‘a‘:‘n‘, ‘b‘:‘o‘, ‘c‘:‘p‘, ‘d‘:‘q‘, ‘e‘:‘r‘, ‘f‘:‘s‘, ‘g‘:‘t‘, ‘h‘:‘u‘,
       ‘i‘:‘v‘, ‘j‘:‘w‘, ‘k‘:‘x‘, ‘l‘:‘y‘, ‘m‘:‘z‘, ‘n‘:‘a‘, ‘o‘:‘b‘, ‘p‘:‘c‘,
       ‘q‘:‘d‘, ‘r‘:‘e‘, ‘s‘:‘f‘, ‘t‘:‘g‘, ‘u‘:‘h‘, ‘v‘:‘i‘, ‘w‘:‘j‘, ‘x‘:‘k‘,
       ‘y‘:‘l‘, ‘z‘:‘m‘, ‘A‘:‘N‘, ‘B‘:‘O‘, ‘C‘:‘P‘, ‘D‘:‘Q‘, ‘E‘:‘R‘, ‘F‘:‘S‘,
       ‘G‘:‘T‘, ‘H‘:‘U‘, ‘I‘:‘V‘, ‘J‘:‘W‘, ‘K‘:‘X‘, ‘L‘:‘Y‘, ‘M‘:‘Z‘, ‘N‘:‘A‘,
       ‘O‘:‘B‘, ‘P‘:‘C‘, ‘Q‘:‘D‘, ‘R‘:‘E‘, ‘S‘:‘F‘, ‘T‘:‘G‘, ‘U‘:‘H‘, ‘V‘:‘I‘,
       ‘W‘:‘J‘, ‘X‘:‘K‘, ‘Y‘:‘L‘, ‘Z‘:‘M‘}
Your task in this exercise is to implement an encoder/decoder of ROT-13.
Once you‘re done, you will be able to read the following secret message:
   Pnrfne pvcure? V zhpu cersre Pnrfne fnynq!
Note that since English has 26 characters,
your ROT-13 program will be able to both encode and decode texts written in English.
‘‘‘
import string
def  ROT_13(message):
    key = {‘a‘: ‘n‘, ‘b‘: ‘o‘, ‘c‘: ‘p‘, ‘d‘: ‘q‘, ‘e‘: ‘r‘, ‘f‘: ‘s‘, ‘g‘: ‘t‘, ‘h‘: ‘u‘,
           ‘i‘: ‘v‘, ‘j‘: ‘w‘, ‘k‘: ‘x‘, ‘l‘: ‘y‘, ‘m‘: ‘z‘, ‘n‘: ‘a‘, ‘o‘: ‘b‘, ‘p‘: ‘c‘,
           ‘q‘: ‘d‘, ‘r‘: ‘e‘, ‘s‘: ‘f‘, ‘t‘: ‘g‘, ‘u‘: ‘h‘, ‘v‘: ‘i‘, ‘w‘: ‘j‘, ‘x‘: ‘k‘,
           ‘y‘: ‘l‘, ‘z‘: ‘m‘, ‘A‘: ‘N‘, ‘B‘: ‘O‘, ‘C‘: ‘P‘, ‘D‘: ‘Q‘, ‘E‘: ‘R‘, ‘F‘: ‘S‘,
           ‘G‘: ‘T‘, ‘H‘: ‘U‘, ‘I‘: ‘V‘, ‘J‘: ‘W‘, ‘K‘: ‘X‘, ‘L‘: ‘Y‘, ‘M‘: ‘Z‘, ‘N‘: ‘A‘,
           ‘O‘: ‘B‘, ‘P‘: ‘C‘, ‘Q‘: ‘D‘, ‘R‘: ‘E‘, ‘S‘: ‘F‘, ‘T‘: ‘G‘, ‘U‘: ‘H‘, ‘V‘: ‘I‘,
           ‘W‘: ‘J‘, ‘X‘: ‘K‘, ‘Y‘: ‘L‘, ‘Z‘: ‘M‘}
    ROT_13_message=[]
    for words in message:
        if words ==" ":
            ROT_13_message.append(words)
        elif words  in string.punctuation:
            ROT_13_message.append(words)
        else:
            ROT_13_message.append(key[words])
    return(‘‘.join(ROT_13_message))
a=‘P?n‘
print(ROT_13(a))
b=‘Pnrfne pvcure? V zhpu cersre Pnrfne fnynq!‘
print(ROT_13(b))

 

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