Hand in your code in MySchool before midnight today (20 August). A single .py file containing the code in the same order as the given problems. You can use File→New File in IDLE to create the file.

If you can't manage to complete a particular problem please hand in your incomplete code – comment it out if it produces an error.

#Use dir() to see the names that exist in the current scope.
 
dir()
 
#You can use help() to see what dir does.
 
help(dir)
 
#Now define three variables and a list. Feel free to change the values:
 
my_str = "This is an ordinary string"
my_int = 5
my_float = 4.6
my_list = ['A','B','C','D']
 
#Use dir() again. Has anything changed?
 
#Use type() to see the type of each.
 
type(my_str)
...
 
#Now use dir on the four types you defined.
 
dir(my_str)
...
 
#Most of the names are functions that can be applied to the types.
#For example dir(my_str) lists 'upper' so its possible to do the following:
 
my_str.upper()
 
#You can use help to see what each function does:
 
help(my_str.upper)
 
#Use dir and help to select one function to apply to each of the variables
#and the list.

Return the your code for applying the four functions you selected in the last part. Note to use print(my_…) to show the change the function made.

#Define a very simple and naive function to check if an Icelandic proper name belongs to a male
#(e.g. ends with "son").
 
def is_male(proper_name):
	return #add code here

Example usage:

>>> is_male("Örvar Kárason")
True
>>> is_male("Glódís Káradóttir")
False
>>> is_male("Gillian Anderson")
True
>>> is_male("Tucson")
True
>>> is_male("a person")
True

Can you improve the function so it handles some of the false positives in the example above?

Define a function that takes a string (text), list (bad_list) and an optional string (good_str) as arguments. It should return the text-string where all occurances of the string items on the bad-list-list have been replaced by the good-string.

def str_replace(text, bad_list, good=''):
    #add code here
    return text

Example usage:

>>> str_replace("Duck", ['u','c'], '*')
'D**k'
>>> str_replace("Python has strange rules!", ['strange ','has '])
'Python rules!'

Before you can get started with the NLTK corpora you have download it with nltk.download() once.

import nltk

Apply NLTK functions to do the following:

• Import text6 from nltk
• Show the concordance of the word “coconut”
• Find words occuring in similar contexts to “coconut”
• Find the collocations in text6

Write code to do the following with the NLTK:

• List all words starting with 'z' alphabetically in text6
• List all uppercase words in text6 (problem 23 http://www.nltk.org/book/ch01.html#exercises)

You are given a dictionary (string:list) of CFG production rules. Make some changes to the rules and then print them nicely.

rules = {"S": ["NP VP"],
         "VP": ["V NP"],
         "NP": ["Det N", "Adj NP"],
         "N": ["boy", "girl"],
         "V": ["sees", "likes"],
         "Adj": ["big", "small"],
         "Det": ["a", "the"]}
 
#Add code to add the verb "hates" to "V".
 
#Add code to add the nouns "dog" and "cat" to "N".
 
#Add code to print out the rules giving the following output.

Hint: items() https://docs.python.org/3.4/tutorial/datastructures.html#looping-techniques

Expected output (the order of the rules does not matter):

N -> boy | girl | dog | cat
S -> NP VP
NP -> Det N | Adj NP
Adj -> big | small
Det -> a | the
VP -> V NP
V -> sees | likes | hates

#1
my_str.upper()
my_int.str()
my_float.is_integer()
my_list.pop(2)
 
#2
def is_male(proper_name):
    return proper_name[-3:] == "son"
    #return proper_name.endswith("son")
 
# return ... and ' ' in proper_name and proper_name.istitle() and "Gillian" in proper_name
# return ... and proper_name.find(' ') and proper_name.istitle() and proper_name.find("Gillian")
 
#3
def str_replace(text, bad_list, good=''):
    for bad in bad_list:
        text = text.replace(bad, good)
    return text
 
#4
from nltk.book import text6
text6.concordance("coconut")
text6.similar("coconut")
text6.collocations()
 
#5
sorted(w for w in set(text6) if w.startswith('z')) # w[0] == 'z'
sorted(set(w for w in text6 if w.isupper())))
 
#6
rules["N"] += ["dog", "cat"]
rules["V"].append("hates")
 
for left, right in rules.items():
    print(left, "->", ' | '.join(right))