Chapter 7 - Text processing

Question 1

title and capitalize both uppercase their respective first letters and…

Answer 1

lowercase everything else

Question 2

what will this return:
mysentence = “This-should———-be–fun!”
mysentence.split(“-“)

Answer 2

[‘This’, ‘should’, ‘’, ‘’, ‘’, ‘’, ‘’, ‘’, ‘’, ‘’, ‘’, ‘be’, ‘’, ‘fun!’]

every pair of delimeters = 1 empty space

Question 3

what will this return: # 21
comma = “fksjefijefk “
print(comma.isalpha())
print(comma.isalnum())
print(comma.isdigit())

Answer 3

False
False
False

spaces arent alphabetical or alphanumeric or digits!

Question 4

do you need to import string to use the constants?

Answer 4

yes

Question 5

what will this return:
mystring = “welcome to the ipp”
result = mystring.split()
result

Answer 5

[‘welcome,’ ‘to’, ‘the’, ‘ipp’]

always returns single quotes!

Question 6

“abc”.rjust(5)

Answer 6

’ abc’

two spaces, single quotes

Question 7

how would you open a file and read it?

Answer 7

f = open(“filename”, ‘r’)

Question 8

possible modes in an open function:

Answer 8

‘r’ - reading
‘w’ - writing
‘a’ - appending
‘r+’ = read from and write to file

Question 9

what happens if you write to a file that already exists?

Answer 9

the contents get completely replaced

Question 10

open

Answer 10

f = open(“filename”, ‘modekeyletter’)
f = open(“filename”)

second version will open in read mode bcz its the safest

Question 11

write and writelines

Answer 11

write(s)
write a string s to the file

writelines(ls)
writes a list ls to the file

Question 12

files that are opened and used must be…

Answer 12

closed, using the close method
f.close()

Question 13

close

Answer 13

f.close()
closes the file, preventing error

Question 14

writing vs appending to a file

Answer 14

writing starts from beginning and replaces insides, appending adds to existing parts of file

Question 15

read, readlines, and readline

Answer 15

f.read()
reads entire file as one string

f.readlines()
reads file into list of strings, each string representing a line

f.readline()
reads one individual line from the file as a string

returns either empty string or list based on what the read returns normally if it is called after the whole file has already been read. Because empty strings are an alt way to say False, you can do a
aline = f.readline()
while aline:

and itll run until readline returns an empty

(does this mean you can call readlines() and if you call read() it will produce a empty string?)

Question 16

how to use with statement?

Answer 16

with open(filename) as f:
#stuff

closes automatically outside of the code block!

Question 17

whats going on with the /n’s at the end of each line? rstrip method? what? (look over lecture notes)

Question 19

what do read, readlines, and readline return if theyve already read the whole file?