Python: Dictionary

Quick diving into "dictionary" of the python.
Actually, this is example of code was written as a simple explanation for my little brother how to work with dictionary. This is simple example, without deep diving for many possible situations.


[code language="python"]

# School class 1A
a1 = {'1a_st_01': 'ivanov',
'1a_st_02': 'petrov',
'1a_st_03': 'sidorov'}
# School class 1B
b1 = {'1b_st_01': 'sidorova',
'1b_st_02': 'kuskina',
'1b_st_03': 'sinicina'}
# School class @a
a2 = {'2a_st_01': 'dilda',
'2a_st_02': 'senechkin'}

school = a1, b1, a2

# Count number of students in all classes
AllStudents = len(a1) + len(b1) + len(a2)
print "1. \n All number of students in school: %d" % AllStudents

"""
Result:
1.
All number of students in school: 8
"""

# Count number of students by school>class
print '2.'
print " Number of Students in 1a klass: %d" % len(a1)
print " Number of Students in 1b class: %d" % len(b1)
print " Number of Students in 2a class: %d" % len(a2)
print '\n'

"""
Result:
2.
Number of Students in 1a klass: 3
Number of Students in 1b class: 3
Number of Students in 2a class: 2
"""

# Print last name of students from "1b" class
keys = b1.keys()
values = b1.values()
print "\nLast Names students from \"1B\" class: ", values
for k, v in b1.iteritems():
b1[k] = v.split()
print v

"""
Result:
Last Names students from "1B" class: ['sidorova', 'kuskina', 'sinicina']
sidorova
kuskina
sinicina
"""

# Add student to 2A class
print "\nAdd new student to 2A class"
a2['2a_st_03'] = 'soloviova'
print "Number of Students in 2A class now: %d" % len(a2)

print "\nClass 1B contain next last names of students"

# Loop and display tuple items.
for k, v in b1.items():
#print(k, ' ==> ', v)
print v

"""
Result:
Class 1B contain next last names of students
['sidorova']
['kuskina']
['sinicina']
"""

# Merge two school classes 1a + 1b true "dict" method
a1b1 = dict(a1.items() + b1.items())
print "\nMerged \"1A\" and \"1B\" classes:\n", a1b1

print "\nName of All students in new/merged class: "
for k, v in a1b1.items():
print "Last Name; ", v
print '\n'

"""
Result:
\nLast Name; ['sidorova']
Last Name; ['kuskina']
Last Name; ['sinicina']
Last Name; sidorov
Last Name; petrov
Last Name; ivanov
"""

# Merge two school classes 1a + 1b true "update" method
a1.update(a2)
for k, v in a1.items():
print "1A, Last Name; ", v

"""
Result:
1A, Last Name; sidorov
1A, Last Name; petrov
1A, Last Name; ivanov
1A, Last Name; senechkin
1A, Last Name; soloviova
1A, Last Name; dilda
"""

print '\n4.', '\n ', "All info: ", school

"""
All info: ({'1a_st_03': 'sidorov', '1a_st_02': 'petrov', \
'1a_st_01': 'ivanov', '2a_st_02': 'senechkin', '2a_st_03': 'soloviova', \
'2a_st_01': 'dilda'}, {'1b_st_01': ['sidorova'], '1b_st_02': ['kuskina'], \
'1b_st_03': ['sinicina']}, {'2a_st_02': 'senechkin', '2a_st_03': 'soloviova', \
'2a_st_01': 'dilda'})
"""

[/code]