Write a brief description of all the following Object Types and Data Structures we've learned about:
For the full answers, review the Jupyter notebook introductions of each topic!
In [10]:
# Your answer is probably different
(20000 - (10 ** 2) / 12 * 34) - 19627.75
Out[10]:
Explain what the cell below will produce and why. Can you change it so the answer is correct?
In [11]:
2/3
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Answer: Because Python 2 performs classic division for integers. Use floats to perform true division. For example: 2.0/3
Answer these 3 questions without typing code. Then type code to check your answer.
What is the value of the expression 4 * (6 + 5)
What is the value of the expression 4 * 6 + 5
What is the value of the expression 4 + 6 * 5
In [16]:
4 * (6 + 5)
Out[16]:
In [17]:
4 * 6 + 5
Out[17]:
In [18]:
4 + 6 * 5
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What is the type of the result of the expression 3 + 1.5 + 4?
Answer: Floating Point Number
What would you use to find a number’s square root, as well as its square?
In [14]:
100 ** 0.5
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In [12]:
10 ** 2
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Given the string 'hello' give an index command that returns 'e'. Use the code below:
In [19]:
s = 'hello'
# Print out 'e' using indexing
s[1]
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Reverse the string 'hello' using indexing:
In [21]:
s ='hello'
# Reverse the string using indexing
s[::-1]
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Given the string hello, give two methods of producing the letter 'o' using indexing.
In [22]:
s ='hello'
# Print out the
s[-1]
Out[22]:
In [23]:
s[4]
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Build this list [0,0,0] two separate ways.
In [25]:
#Method 1
[0]*3
Out[25]:
In [27]:
#Method 2
l = [0,0,0]
l
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Reassign 'hello' in this nested list to say 'goodbye' item in this list:
In [28]:
l = [1,2,[3,4,'hello']]
In [31]:
l[2][2] = 'goodbye'
In [32]:
l
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Sort the list below:
In [1]:
l = [5,3,4,6,1]
In [2]:
#Method 1
sorted(l)
Out[2]:
In [3]:
#Method 2
l.sort()
l
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Using keys and indexing, grab the 'hello' from the following dictionaries:
In [41]:
d = {'simple_key':'hello'}
# Grab 'hello'
In [42]:
d['simple_key']
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In [43]:
d = {'k1':{'k2':'hello'}}
# Grab 'hello'
In [44]:
d['k1']['k2']
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In [45]:
# Getting a little tricker
d = {'k1':[{'nest_key':['this is deep',['hello']]}]}
In [51]:
# This was harder than I expected...
d['k1'][0]['nest_key'][1][0]
Out[51]:
In [52]:
# This will be hard and annoying!
d = {'k1':[1,2,{'k2':['this is tricky',{'tough':[1,2,['hello']]}]}]}
In [61]:
# Phew
d['k1'][2]['k2'][1]['tough'][2][0]
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Can you sort a dictionary? Why or why not?
Answer: No! Because normal dictionaries are mappings not a sequence.
What is the major difference between tuples and lists?
Tuples are immutable!
How do you create a tuple?
In [63]:
t = (1,2,3)
What is unique about a set?
Answer: They don't allow for duplicate items!
Use a set to find the unique values of the list below:
In [64]:
l = [1,2,2,33,4,4,11,22,3,3,2]
In [65]:
set(l)
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For the following quiz questions, we will get a preview of comparison operators:
| Operator | Description | Example |
|---|---|---|
| == | If the values of two operands are equal, then the condition becomes true. | (a == b) is not true. |
| != | If values of two operands are not equal, then condition becomes true. | |
| <> | If values of two operands are not equal, then condition becomes true. | (a <> b) is true. This is similar to != operator. |
| > | If the value of left operand is greater than the value of right operand, then condition becomes true. | (a > b) is not true. |
| < | If the value of left operand is less than the value of right operand, then condition becomes true. | (a < b) is true. |
| >= | If the value of left operand is greater than or equal to the value of right operand, then condition becomes true. | (a >= b) is not true. |
| <= | If the value of left operand is less than or equal to the value of right operand, then condition becomes true. | (a <= b) is true. |
What will be the resulting Boolean of the following pieces of code (answer fist then check by typing it in!)
In [66]:
# Answer before running cell
2 > 3
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In [67]:
# Answer before running cell
3 <= 2
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In [68]:
# Answer before running cell
3 == 2.0
Out[68]:
In [69]:
# Answer before running cell
3.0 == 3
Out[69]:
In [70]:
# Answer before running cell
4**0.5 != 2
Out[70]:
Final Question: What is the boolean output of the cell block below?
In [71]:
# two nested lists
l_one = [1,2,[3,4]]
l_two = [1,2,{'k1':4}]
#True or False?
l_one[2][0] >= l_two[2]['k1']
Out[71]: