Section 3.8 - IT 140_ Introduction to Scripting _ zyBooks

 Students: Section 3.8 is a part of 1 assignment: 3-1 zyBooks Participation Activities Includes: PA 3.8 Code blocks and indentation Code blocks A code block is a series of statements that are grouped together. A code block in Python is de±ned by its indentation level, i.e., the number of blank columns from the left edge. The initial code block is not indented. A new code block can follow a statement that ends with a colon, such as an "if" or "else". In addition, a new code block must be more indented than the previous code block. The program below includes comments indicating where each new code block begins. The amount of indentation used to indicate a new code block can be arbitrary, as long as the programmer uses the same indentation consistently for each line in the block. Good practice is to use the standard recommended 4 columns per indentation level. A common error for new Python programmers is the mixing of tabs and spaces. Never mix tabs and spaces for indentation in the same program. Many editors consider a tab to be equivalent to either 3 or 4 spaces, while in Python a tab is equivalent only to another tab. A program that mixes tabs and space to indent code blocks will automatically generate an IndentationError from the interpreter in Python 3. A good practice is to use spaces only when indenting code, and to set text editor options to automatically use spaces when possible. Figure 3.8.1: Code blocks are indicated with indentation. # First code block has no indentation model = input ( 'Enter car model: ' ) year = int ( input ( 'Enter year of car manufacture: ' )) antique = False domestic = False if year < 1970 : # New code block has indentation of 4 columns antique = True # Back to code block 0 if model in [ 'Ford' , 'Chevrolet' , 'Dodge' ]: # New code block has indentation of 2 columns # Any amount of indentation > 0 is OK. domestic = True # Back to code block 0 if antique : # New code block has indentation of 4 columns if domestic : # New block has 4 additional columns (8 total) print ( 'My own model-T still runs like a charm...' ) Enter car model: Ford Enter year of car manufacture: 1918 My own model-T still runs like a charm... zyDE 3.8.1: Code blocks and indentation. Fix the errors in the code below so that you can run the program. 160000 Runtime error File "/home/runner/local/submission/mai line 4 import math IndentationError: unexpected indent Special cases The number of columns of text considered to be acceptable varies from 80 to 120. Good practice is to use the widely accepted standard of 80 columns. A few exceptions to the rules of indentation deal with very long statements that require more than one line and wrap to the next line. Such special situations do not indicate new code blocks. Figure 3.8.2: Some indentations are continuations of the previous line. Multiple lines enclosed within parentheses are implicitly joined into a single string (without newlines between each line); use implicit line joining for very long strings or functions with numerous arguments. Ex: All extra lines are indented to the same column as the opening quotation mark on the ±rst line. When declaring list or dict literals, entries can be placed on separate lines for clarity. Feedback? Load default template... # Calculate the velocity required to # depending on a user-entered orbita import math escape_velocity_meters_per_sec = 0 grav_constant = 6.67384e-11 # Eart earth_mass_kilograms = 5.972e24 radius_meters = float ( input ( '160 print () if radius_meters < 6317000: # 6317 print ( 'Houston, we have a pr else : standard_grav_param = grav_con Run Feedback? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18