#!/usr/bin/env python# coding: utf-8# # Lab 1: Introduction to Python# # Welcome to Lab 1! Each week you will complete a lab assignment like this one.In this lab, you'll get started with the Python programming language through numbers, names, and expressions.# # As you go, please regularly select **Save and Checkpoint** from the `File` menu below the Jupyter logo to save your work.# ## 1. Numbers# # Quantitative information arises everywhere in data science. In addition to representing commands to print out lines, expressions can represent numbers and methods of combining numbers. The expression `3.2500` evaluates to the number 3.25. (Run the cell and see.)# In[1]:3.2500# Notice that we didn't have to `print`. When you run a notebook cell, if the last line has a value, then Jupyter helpfully prints out that value for you. However, it won't print out prior lines automatically. If you want to print out a prior line, you need to add the `print` statement. Run the cell below to check.# In[2]:print(2)34# Above, you should see that 4 is the value of the last expression, 2 is printed, but 3 is lost forever because it was neither printed nor last.# # You don't want to print everything all the time anyway. But if you feel sorryfor 3, change the cell above to print it.# ### 1.1. Arithmetic# The line in the next cell subtracts. Its value is what you'd expect. Run it.# In[3]:3.25 - 1.5# Many basic arithmetic operations are built in to Python. The textbook sectionon [Expressions]() describes all the arithmetic operators used in the course. The common operator that differs from typical math notation is `**`, which raises one number to the powerof the other. So, `2**3` stands for $2^3$ and evaluates to 8. # # The order of operations is what you learned in elementary school, and Python also has parentheses. For example, compare the outputs of the cells below. Use parentheses for a happy new year!

# In[4]:3+6*5-6*3**2*2**3/4*7# In[5]:3+(6*5-(6*3))**2*((2**3)/4*7)# In standard math notation, the first expression is# # $$3 + 6 \times 5 - 6 \times 3^2 \times \frac{2^3}{4} \times 7,$$# # while the second expression is# # $$3 + (6 \times 5 - (6 \times 3))^2 \times (\frac{(2^3)}{4} \times 7).$$# # **Question 1.1.1.** <br /> Write a Python expression in this next cell that's equal to $5 \times (3 \frac{10}{11}) - 49 \frac{1}{3} + 2^{.5 \times 22} + \frac{26}{33}$. That's five times three and ten elevenths, minus 49 and a third, plus two to the power of half of 22, plus 26 33rds. By "$3 \frac{10}{11}$" we mean $3+\frac{10}{11}$, not $3 \times \frac{10}{11}$.# # Replace the ellipses (`...`) with your expression. Try to use parentheses only when necessary.# # *Hint:* The correct output should be a familiar number.# In[6]:5*(3+10/11)-(49+1/3)+2**(.5*22)+26/33# ## 2. Names# In natural language, we have terminology that lets us quickly reference very complicated concepts. We don't say, "That's a large mammal with brown fur and sharp teeth!" Instead, we just say, "Bear!"# # Similarly, an effective strategy for writing code is to define names for data as we compute it, like a lawyer would define terms for complex ideas at the start of a legal document to simplify the rest of the writing.

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