20211106,20211107
suspended 2 days for tinkering my desktop. I've bought a 16Gbytes Samsung SDRAM, that's so great.
10-1
with open('learning_python.txt') as file_object:
contents = file_object.read()
print(contents)
print('n')
with open('learning_python.txt') as file_object:
for line in file_object:
print(line.rstrip())
print('n')
with open('learning_python.txt') as file_object:
l_p = []
for line in file_object:
l_p.append(line.rstrip())
for l in l_p:
print(l)
10-2
with open('learning_python.txt') as file_object:
contents = []
for line in file_object:
contents.append(line.replace('Python', 'C'))
for c in contents:
print(c.rstrip())
10-3
with open('guest.txt', 'w') as file:
print('enter 1 to quit')
while True:
guest = input('plz enter ur name:')
if guest == '1':
break
else:
file.write(guest + 'n')
10-4
import time
with open('guest.txt', 'w') as file:
print('enter q to quit')
while True:
guest = input('plz enter ur name:')
if guest == 'q':
break
else:
file.write(guest + ': ' + time.strftime('%Y-%m-%d %H:%M:%S',
time.localtime()) + 'n')
print("What's up! " + guest.title())
10-5
with open('reason.txt', 'a') as file:
print('enter q to quit')
while True:
reason = input('why do u like coding:')
if reason == 'q':
break
else:
file.write(reason + 'n')
10-6
print('nenter 2 numbers, I will add them ')
num1 = input('first number: ')
num2 = input('second number: ')
try:
num = float(num1) + float(num2)
except ValueError:
print('u can only input numbers')
else:
print('nanswer: ' + str(num))
10-7
while True:
print('nenter 2 numbers, I will add them ')
print('enter "q" to quit')
num1 = input('first number: ')
if num1 == 'q':
break
else:
num2 = input('second number: ')
try:
num = float(num1) + float(num2)
except ValueError:
print('u can only input numbers')
else:
print('nanswer: ' + str(num))
10-8
try:
with open('cats.txt') as f1:
contents1 = f1.read()
print('cats:n' + contents1)
with open('dogs.txt') as f2:
contents2 = f2.read()
print('ndogs:n' + contents2)
except FileNotFoundError:
print('u should put files in the same place of this .py')
10-9
try:
with open('cats.txt') as f1:
contents1 = f1.read()
print('cats:n' + contents1)
with open('dogs.txt') as f2:
contents2 = f2.read()
print('ndogs:n' + contents2)
except FileNotFoundError:
pass
-------------------------------------------------------------------------------
REVISED:
filenames = ['cats.txt', 'dogs.txt']
for filename in filenames:
try:
with open(filename) as f:
contents = f.read()
except FileNotFoundError:
pass
else:
print("nReading file: " + filename)
print(contents)
-------------------------------------------------------------------------------
10-10
with open('Hard Times.txt', 'r', encoding='utf-8') as f:
#---------------------------------------------, 'r', encoding='utf-8 is pivotal
c = f.read()
n = c.lower().count('hard')
print("nums of 'the': " + str(n))
10-11
import json
num = int(input('plz enter ur favorite number:'))
with open('favorite_number.json','w') as f:
json.dump(num, f)
with open('favorite_number.json') as f:
nums = json.load(f)
print(nums)
10-12
import json
try:
with open('george.json') as f:
num = json.load(f)
except FileNotFoundError:
with open('george.json','w') as f:
num = int(input('plz enter ur favorite number:'))
json.dump(num, f)
else:
print('ur favorite num is ' + str(num))
10-13
import json
def get_stored_username():
"""Get stored username if available."""
filename = 'username.json'
try:
with open(filename) as f_obj:
username = json.load(f_obj)
except FileNotFoundError:
return None
else:
return username
def get_new_username():
"""prompt for a new username."""
username = input("What is your name? ")
filename = 'username.json'
with open(filename, 'w') as f_obj:
json.dump(username, f_obj)
return username
def verify(username):
man = input('are u ' + username.title() + ' ?(y/n)' )
if man == 'y':
print("Welcome back, " + username + "!")
else:
username = get_new_username()
print("We'll remember you when you come back, " + username + "!")
def greet_user():
"""Greet the user by name."""
username = get_stored_username()
if username:
verify(username)
else:
username = get_new_username()
print("We'll remember you when you come back, " + username + "!")
greet_user()
