#!/usr/bin/env python3

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

# String formatting practice

#

x = 3.7925

y = 1.3e10

x_name = "x"

y_name = "y"

# Create a formatted string and print it out

# Use "".format with {} OR the f"" syntax

# DON'T copy the stuff from the variables above into the string - if you change any of the variable values above

# it should still work

# LO: Use of {} in a string with format

# First version - modify one (or both) of the print statements below to produce:

# First variable is x, value 3.7925, second variable is y, value 13000000000.0

print("First variable is , value , second variable is , value ".format())

print(f"First variable is , value , second variable is , value ")

# LO: Use of modifiers in {} to format numbers

# Second version - modify one (or both) of the print statements below to produce:

# First variable is x, value 3.79, second variable is y, value 1.30e+10

# LO: Can do equations in format, newline (\n) and tab (\t)

# Third version - modify one (or both) of the print statements below to produce:

# - do this with ONE print statement, using \n, and without creating new variables

# - hint mu is (x + y) / 2

# Variables (x, y), values (3.79, 1.30e+10),

# mu 6500000001.90

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

# Splitting up long strings into text and numbers

#

# LO: String indexing, building one string from multiple ones (use + or "".format or f"")

# Change my_new_fname to be "foo.csv" instead of "foo.txt'

# You must use my_fname - don't just type in the values. This should work even if you change foo to something else

# Should output:

# Old file name: foo.txt, New file name: foo.csv

my_fname = "foo.txt"

my_new_fname = my_fname

print(f"Old file name: {my_fname}, New file name: {my_new_fname}")

# LO: Find (and replace) dashes or other special characters in a string

# Replace the dash with a space

# Should output:

# Dashed: a-dash, not dashed: a dash

str_with_dash = "a-dash"

str_without_dash = str_with_dash

print(f"Dashed: {str_with_dash}, not dashed: {str_without_dash}")

# Do these in order

# LO: strip for removing unwanted characters

# First change: Take out the () so a string and 10 don't have parenthesis in them

# Second change: Remove extra white space so everything prints left-justified

# - hint: strip with no parameters will take out ALL white space (including tabs and new lines)

# - you can do the strip on the ENTIRE string OR on each individual one - doesn't really matter

# LO: Using the .isxxx() methods to determine if the string is an integer or not

# Third change: Print out either "Is an integer [the number]" or "Is not an integer [the string]" for each string

# - you will have to do this on individual strings AND add an if statement into the for loop...

# - [optional] if you want to detect 3.7 or 1e30 you need to try converting to a number and then throw an

# exception if it didn't work - see answers below

# LO: Use the cast int() or float() to convert a string to a number

# Fourth change: Add 2 to the number before printing it out

# Fifth change: take out any dashes or ' in the strings

# LO: Putting strings together in a for loop (how to do an append), str() to convert a number to a string

# You will need to do the following, because you can't edit strings in place - this creates a new string from the

# old one plus the new stuff

# my_new_str

# for [blah]

# my_new_str = my_new_str + [new stuff]

# OR

# my_new_str = f"{my_new_str} new stuff"

#

# Glue the string back together. The for loop and the final print should produce:

# Is not an integer: a string

# Is not an integer: 3.7

# Is not an integer: a dash

# Is not an integer: 1e30

# Is an integer: 7, adding two: 9

# Is not an integer: a tick

# Is an integer: 10, adding two: 12

# My fixed string: (a string, 3.7, a dash, 1e30, 9, a tick, 12)

#

my_long_str = "(a string, 3.7, a-dash, 1e30, 7, a'tick, \n \t 10)"

my_fixed_str = my_long_str

for my_str in my_long_str.split(","):

print(f"{my_str}")

print(f"My fixed string: {my_fixed_str}")

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

# ANSWERS

print("-"*10 + "ANSWERS" + "-"*10)

print("First version")

print("First variable is {}, value {}, second variable is {}, value {}".format(x_name, x, y_name, y))

print(f"First variable is {x_name}, value {x}, second variable is {y_name}, value {y}")

print("Second version")

print("First variable is {}, value {:0.2f}, second variable is {}, value {:0.2e}".format(x_name, x, y_name, y))

print(f"First variable is {x_name}, value {x:0.2f}, second variable is {y_name}, value {y:0.2e}")

print("Third version")

print("Variables ({}, {}), values ({:0.2f}, {:0.2e}), \n\tmu {:0.2f}".format(x_name, y_name, x, y, (x + y) / 2))

print(f"Variables ({x_name}, {y_name}), values ({x:0.2f}, {y:0.2e}), \n\tmu {((x + y) / 2):0.2f}")

# --------

print("-"*20)

# I like plus in this case (rather than format) because you're just putting two strings together

my_new_fname_v1 = my_fname[:-4] + ".csv"

# But this works too

my_new_fname_v2 = f"{my_fname[:-4]}.csv"

# And this...

my_new_fname_v3 = "{}.csv".format(my_fname[:-4])

# Print out the new file names

print(f"Old file name: {my_fname}, New file name: {my_new_fname_v1}")

print(f"Old file name: {my_fname}, New file name: {my_new_fname_v2}")

print(f"Old file name: {my_fname}, New file name: {my_new_fname_v3}")

# --------

# Simplest dash replace:

str_without_dash = str_with_dash.replace("-", " ")

print(f"Dashed: {str_with_dash}, not dashed: {str_without_dash}")

# You can also use find and string indexing to do it manually

index_dash = str_with_dash.find("-")

str_without_dash = str_with_dash[0:index_dash] + " " + str_with_dash[index_dash+1:]

print(f"Dashed: {str_with_dash}, not dashed: {str_without_dash}")

# ----

# This strips out both the ( and the ) from the string

# You COULD do the following if you want to strip out all the white space at the same time:

my_do_it_all = my_long_str.strip("()").strip() # optional

print(my_do_it_all)

m_long_str_modified = my_long_str.strip("()") # Or just take out the () and do the white space later

# Building the new string

my_fixed_string = "(" # Start with the (

# Split returns a list of strings, removing the ,

# The for loop will assign my_str to each of those strings in the list in turn

for my_str in m_long_str_modified.split(","):

# Remove the white space - don't pass in parameters if you want strip to remove ALL types of white space

my_str_modified = my_str.strip()

# See if we have a digit

if my_str_modified.isdigit():

# Note the conversion to int - you can't add 2 to a string

my_num = int(my_str_modified) + 2

# Note the my_fixed_string = my_fixed_string - you can't edit my_fixed_string, but you can make a new

# string from my_fixed_string and then assign that to the same variable

my_fixed_string = my_fixed_string + str(my_num) + ", " # Note the cast back to a str

# Print statement

print(f"Is an integer: {my_str_modified}, adding two: {my_num}")

else:

# You can do this one at a time - note that my_str_modified is on the left and right (rather than creating

# a new variable)

my_str_modified = my_str_modified.replace("-", " ")

my_str_modified = my_str_modified.replace("'", " ")

# OR

my_str_modified = my_str_modified.replace("-", " ").replace("'", " ")

# See above about building my_fixed_string

my_fixed_string = my_fixed_string + my_str_modified + ", "

# Print statement

print(f"Is not an integer: {my_str_modified}")

# Take out the last comma and add the )

my_fixed_string = my_fixed_string[0:-2] + ")"

print(f"My fixed string: {my_fixed_string}")

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

# OPTIONAL - doing it the fancy way with join and a list

# This version is a bit "easier" to debug, because we split up the string, then store each piece in the list,

# and wait until the end to put the list back together. This separates out two conceptual steps - splitting up and

# editing the original list, and sticking the list back together into a string.

my_fixed_strs_fancy = [] # where to put the fixed strings

# Outer for loop is the same

for my_str in m_long_str_modified.split(","):

# Remove the white space - don't pass in parameters if you want strip to remove ALL types of white space

my_str_modified = my_str.strip()

# See if we have a digit

if my_str_modified.isdigit():

# Note the conversion to int - you can't add 2 to a string

my_num = int(my_str_modified) + 2

# Convert back to a string

my_num_str = str(my_num)

# Put the new string in the list - note the str() to cast the number to a string

my_fixed_strs_fancy.append(my_num_str)

# Print statement

print(f"Is an integer: {my_str_modified}, adding two: {my_num}")

else:

# Do all the modifications at once

my_str_modified = my_str_modified.replace("-", " ").replace("'", " ")

# Put the new string in the list

my_fixed_strs_fancy.append(my_str_modified)

# Print statement

print(f"Is not an integer: {my_str_modified}")

# This is the more elegant way to do this, building a list of strings then using join to put them together with ,s

my_fixed_string_fancy = "(" + ", ".join(my_fixed_strs_fancy) + ")"

print(f"My fixed string fancy: {my_fixed_string_fancy}")

# OPTIONAL - if you want to do the decimals/other number formats, the right thing to do is TRY to cast the

# string to a number and then, if it fails, assume it is not a number

my_fixed_strs_fancy = []

for my_str in m_long_str_modified.split(","):

# Don't need to remove the white space because the cast will do it

try:

# Try to cast to a float and add two

my_num = float(my_str) + 2

my_str_modified = str(my_num) # You could do these in one line, but...

print(f"Is a number: {my_str_modified}")

except ValueError:

# If the above code failed, do this instead

my_str_modified = my_str.strip().replace("-", " ").replace("'", " ")

print(f"Is not a number: {my_str_modified}")

my_fixed_strs_fancy.append(my_str_modified)

my_fixed_string_fancy = "(" + ", ".join(my_fixed_strs_fancy) + ")"

print(f"My fixed string fancy: {my_fixed_string_fancy}")