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--- public:t-malv-15-3:1 [2018/08/15 21:58] – Hiding orvark
+++ public:t-malv-15-3:1 [2024/04/29 13:33] (current) – external edit 127.0.0.1
@@ Line 1: / Line 1: @@
 ====== Lab 1 ======
+**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.
+===== 1. Getting to know some helpful functions =====
+<code python>
+#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.
+</code>
+**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.
+===== 2. Naive is_male =====
+<code python>
+#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
+</code>
+Example usage:
+<code>
+>>> is_male("Örvar Kárason")
+True
+>>> is_male("Glódís Káradóttir")
+False
+>>> is_male("Gillian Anderson")
+True
+>>> is_male("Tucson")
+True
+>>> is_male("a person")
+True
+</code>
+**Can you improve the function so it handles some of the false positives in the example above?**
+===== 3. Replace bad with good =====
+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 It should return the text-string where all occurances of the string items on the bad-list-list have been replaced by the good-string.
+<code python>
+def str_replace(text, bad_list, good=''):
+    #add code here
+    return text
+</code>
+Example usage:
+<code>
+>>> str_replace("Duck", ['u','c'], '*')
+'D**k'
+>>> str_replace("Python has strange rules!", ['strange ','has '])
+'Python rules!'
+</code>
+===== 4. NLTK functions =====
+Before you can get started with the NLTK corpora you have download it with nltk.download() once.
+<code python>
+import nltk
+</code>
+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
+===== 5. NLTK coding =====
+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]])
+===== 6. A dictionary of rules =====
+You are given a dictionary (string:list) of CFG production rules. Make some changes to the rules and then print them nicely.
+<code python>
+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.
+</code>
+//Hint: items() [[https://docs.python.org/3.4/tutorial/datastructures.html#looping-techniques]]//
+Expected output (the order of the rules does not matter):
+<code>
+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
+</code>
+===== Possible Solutions =====
+<code python>
+#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))
+</code>