"""
CS101 Example uses of dictionaries
"""

import string

# List review

def find_max(L):
    """
    Finds and returns the max element in list L
    """

    m = L[0]            # declare the first element to be our starting point
    for item in L:      # for every item in the list
        if item > m:    # if the item is greater than our current maximum
            m = item    # make the item the NEW current maximum

    return m            # give back the max after checking every element


# Packing and unpacking

def find_min_max(L):
    """
    Returns an implicitly packed tuple containing the
    min and max values in L.
    """

    minimum = L[0]          # set max and min to be the first element in L
    maximum = L[0]
    for item in L:          # for every item in L
        if item > maximum:  # if it is greater than max
            maximum = item  # make it the new max
        if item < minimum:  # if it is less than the min
            minimum = item  # make it the new min
    return minimum, maximum # return a tuple with min, max

#-----------------------------------------------------------------

def unpack_min_max(L):
    """
    Shows how we can unpack a function call
    that returns multiple elements.
    """

    m1, m2 = find_min_max(L)    # make a call to find_min_max() and unpack
                                # the 2 item tuple it returns into m1 and m2
    print(m1)
    print(m2)

#-----------------------------------------------------------------

# Dictionaries

def german_dict():
    """
    Creates and returns a small German-to-English dictionary.
    """
    german = dict()  # create empty dictionary

    german['cat'] = 'die Katze'
    german['dog'] = 'der Hund'
    german['to see'] = 'sehen'
    german['to drive'] = 'fahren'
    german['sun'] = 'die Sonne'

    return german

def print_iteration(d):
    """
    Iterates through a dictionary and prints the iterator (keys)
    """

    for key in d:
        print(key)

def print_keys(d):
    """
    Explicitly iterates through the keys of a dictionary
    """

    for k in d.keys():
        print(k)

def print_values(d):
    """
    Iterates through the values of a dictionary
    (does not show the keys).
    """

    for v in d.values():
        print(v)

def print_items(d):
    """
    Uses unpacking to print key, value pairs
    """

    for k, v in d.items():
        print("Key is: " + k + " -- " + "Value is: " + v)


#-----------------------------------------------------------------

# Files

def print_lines(filename):
    """
    Prints out each line of a file.
    """

    f = open(filename, encoding="utf-8")    # open the file as unicode document

    for line in f:      # for each line in the file
        print(line)     # print the line

def process_file(filename):
    """
    Opens a text file and processes each line, printing
    each clean word
    """

    f = open(filename, encoding="utf-8")    # open the file as unicode document

    for line in f:                      # for every line in the file
        words = line.strip().split()    # make a list of words
        for w in words:                 # for every word in the list of words
            no_punc_w = clean(w)        # clean the word
            print(no_punc_w)            # and print it out

def clean(s):
    """
    Removes all punctuation (including internal) from a
    string s.
    """

    for char in string.punctuation: # for every character in the
                                    # string.punctuation constant
        s = s.replace(char,'')      # replace the char in s with nothing
                                    # (i.e. "erase it")
    return s                        # give back the clean version of s