So I'm in a beginner Python course trying to learn my first language. I've managed to make it this far, but I'm struggling with this. I want to use a module to perform a function. However, it seems to be completely ignoring my module.
Any suggestions?
import asgn4_module as mod
"""
imports the module, and then prints intro
"""
print ("Assignment 4")
print ()
"""
prompts for names and age.
If they're blank, reprompts them.
"""
firstname = (input ("Please enter your first name."))
while mod.is_field_blank (firstname):
print ("First Name must be entered.")
firstname = (input ("Please enter your first name."))
continue
lastname = (input ("Please enter your last name."))
while mod.is_field_blank (lastname):
print ("Last name must be entered.")
lastname = (input ("Please enter your last name."))
continue
age =(input ("Please enter your age."))
while mod.is_field_blank (age):
print ("Age must be entered.")
age =(input ("Please enter your age."))
continue
while mod.is_field_a_number (age):
print ("Age entered must be a number.")
age =(input ("Please enter your age."))
continue
"""
inputs all received properly, print message calling those variables, then prints the end
"""
if int(age) >= 40:
print ("Well, " + firstname + " " + lastname + "it looks like you're over the hill.")
else:
print ("It looks like you have many programming years ahead of you, " + firstname + " " + lastname)
print ()
print ("End of assignment 4")
This is asgn4_module.py
"""
this module determines if the string is blank, or a number.
"""
def is_field_blank (string):
string == ""
def is_field_a_number (string):
string is int
You are not checking empty but input string against 'g' which I think is not the correct as you have explain your code. And you also have to return the case condition.
Update your module like this
"""
this module determines if the string is blank, or a number.
"""
def is_field_blank (string):
return False if len(string) else True
# for python3
def is_field_a_number (string):
return not string.isnumeric
for python2
# for python2
def is_field_a_number (string):
return not isinstance(string, int)
Related
So I have for example the following while statements and I would like to combine them. Because this can get tiresome if you have 20 of these with all different if statements.
while True:
name = str(raw_input("NAME PLEASE\n"))
if name.isalpha():
break
print("Please chars dude")
while True:
age = raw_input("Please type your age\n")
if age.isdigit():
break
print("Please digits only")
If I combine them and someone types a A-Z character with 'age' then the code restarts all over without having saved the 'name' statement. I would like it to save 'name' if it's correct and only start over from the if statement that was false.
while True:
name = str(raw_input("NAME PLEASE\n"))
if name.isalpha():
break
print("Please chars dude")
age = raw_input("Please type your age\n")
if age.isdigit():
break
print("Please digits only")
Use a function to encapsulate asking for information. You can pass in a validation test function:
def ask(question, validator, errormessage):
while True:
result = raw_input(question)
if not validator(result):
print(errormessage)
continue
return result
name = ask("NAME PLEASE\n", lambda s: s.isalpha(), "Please chars dude")
age = ask("Please type your age\n", lambda s: s.isdigit(), "Please digits only")
This is far more readable then any number of tests to see if the user already entered a correct name and you only need to ask for the age now.
Why not use functions and cut down on some duplication in the process?
def ask_input(prompt, error_msg, validation_fn):
while True:
data = raw_input(prompt)
if validation_fn(data):
return data
print(error_msg)
name = ask_input("NAME PLEASE\n", "Please chars dude", lambda x: x.isalpha())
age = ask_input("Please type your age\n", "Please digits only",
lambda x: x.isdigit())
In this case, the prompt (what to ask the user), an error message (what to provide on invalid input), and a validation function are provided to the ask_input() function. This hides the while loop behind the function call and gives you something more meaningful to read in the code.
The lambda functions are just an easy way to help do the validation. You could do this instead:
def isalpha(x):
return x.isalpha()
def isdigit(x):
return x.isdigit()
name = ask_input("NAME PLEASE\n", "Please chars dude", isalpha)
age = ask_input("Please type your age\n", "Please digits only", isdigit)
You can set the variables to None first, and then check them before assignment:
name, age = None, None
while True:
if name is None:
name = str(raw_input("NAME PLEASE\n"))
if not name.isalpha():
print("Please chars dude")
name = None
continue
if age is None:
age = raw_input("Please type your age\n")
if not age.isdigit():
print("Please digits only")
age = None
continue
print("input is valid")
break
continue will start the loop over again. This fits better in the logic of your code, since break actually stop and exit the loop code.
Just use flags to track weather valid input is given, if given then exit the loop.
name_input_required = True
name = ''
while name_input_required:
name = str(raw_input("NAME PLEASE\n"))
if name.isalpha():
name_input_required = False
else:
print("Please chars dude")
age_input_required = True
age = None
while age_input_required:
age = raw_input("Please type your age\n")
if age.isdigit():
age_input_required = False
else:
print("Please digits only")
Try this:
name = None
age = None
while requires_info:
if name is None:
temp_name = str(raw_input("NAME PLEASE\n"))
if temp_name.isalpha():
name = temp_name
continue
else:
print("Please chars dude")
continue
if age is None:
temp_age = raw_input("Please type your age\n")
if temp_age.isdigit():
age = temp_age
continue
else:
print("Please digits only")
continue
break
What we do here is use a single continuous loop and a few if statements/variables to track what still needs to be done. Note depending on how you want them to enter the data you may also add logic to not ask for age if the name was invalid.
So I have for example the following while statements and I would like to combine them. Because this can get tiresome if you have 20 of these with all different if statements.
I assume the actual problem is "How to reduce tiresome code?" instead of "How to merge two loops into one?". I think keeping two loops is a good idea.
def safe_input(prompt, err_message, validation_fn):
while True:
value = raw_input(prompt)
if validation_fn(value):
return value
print err_message
name = safe_input("NAME PLEASE\n", "Please chars dude", str.isalpha)
age = safe_input("Please type your age\n", "Please digits only", str.isdigit)
If you always want the used to enter text in a separate line, you might want to print prompt before raw_input and to not give an argument to raw_input. That way you don't have to supply "\n" in every call of safe_input.
Yes, you can combine both loops in one loop!
Always try to solve the problem line by line.
You will get to learn the language better and it is the most simple way to solve any problem too.
A line by line solution would look like this:
name = '' # define name outside while loop
while True:
if not name:
name = str(raw_input("NAME PLEASE\n"))
if not name.isalpha(): # validate name
print("Please chars dude")
# reset name
name = ''
else:
age = raw_input("Please type your age\n")
if age.isdigit(): # validate age
"""continue your code here"""
print('name: ' + name + ' and age: ' + age)
print('Ok! Goodbye!')
break # while loop
else:
print("Please digits only")
will print:
NAME PLEASE
Elis
Please type your age
30
name: Elis and age: 30
Ok! Goodbye!
This will help you understand while loop better and how to use it in more difficult cases.
Do not over design using redundant language features. It will make refactoring and debugging difficult.
strFName = ""
while strFName != strFName.isalpha():
if strFName != strFName.isalpha():
strFName = input("What is your first name? ")
else:
print("Your name cannot contain numbers")
break
I want the user to enter their name, but if they enter any letters the program will throw up an error. So far I am trying to do this with a try and except but whenever I enter a number it just goes straight on to the next part of the program.
You mean the first name cannot contain digits?
If so, you can do something like this:
import string
has_digits = lambda x: any([i.isdigit() for i in x])
first_name = "0"
while has_digits(first_name):
first_name = input("Enter first name (cannot contain digits): ")
print('Your name is {}'.format(first_name))
I have a program that asks the user's name:
while True:
try:
name = str(input("Please enter your name > "))
except ValueError:
print("Please enter a valid name")
continue
else:
break
I want to prevent the user from entering an integer, but with the code above integers are accepted in a string. How can I prevent the user from entering an integer in the string?
Firstly, do not cast str as input returns an str. Note from the docs
The function then reads a line from input, converts it to a string (stripping a trailing newline), and returns that
After you get the input into name you can have a if condition.
name = str(input("Please enter your name > "))
if (re.search('\d',name)):
print("Sorry your name contains a number")
And don't forget to import re
break when trying to cast to an int if an exception is raised as it is not an int:
while True:
name = input("Please enter your name > ")
try:
int(name)
except ValueError:
break
print("Please enter a valid name")
str.digit might work also but will fail on negative input.
To check if any character is a digit use any:
while True:
name = input("Please enter your name > ")
if any(ch.isdigit() for ch in name):
print("Please enter a valid name")
else:
break
You could also create a set of accepted characters:
from string import ascii_letters
st = set(ascii_letters)
while True:
name = input("Please enter your name > ")
if not st.issuperset(name):
print("Please enter a valid name")
else:
break
Where you might want to add -, " " and any other potential characters.
You can use the string method isdigit() to check if the string is just integers.
name = input("Please enter your name: ")
if name.isdigit() == True:
print ("That's not a name!")
Likewise, you can also use the method isalpha() to check if the string is just text. However, if there's a space, it will return False.
name = input("Enter your name: ")
if name.isalpha() != True:
print ("That's not a name!")
Maybe:
if len(set(name) - set('1234567890')) < len(set(name)):
name = input("Please enter a valid name: ")
Hi I just start learning python today and get to apply what I learning on a flash cards program, I want to ask the user for their name, and only accept alphabet without numbers or symbols, I've tried several ways but there is something I am missing in my attempts. Here is what I did so far.
yname = raw_input('Your Name ?: ')
if yname.isdigit():
print ('{0}, can\'t be your name!'.format(yname))
print "Please use alphbetic characters only!."
yname = raw_input("Enter your name:?")
print "Welcome %s !" %yname
but I figured in this one is if the user input any character more than one time it will eventually continue...So I did this instead.
yname = raw_input("EnterName").isalpha()
while yname == True:
if yname == yname.isalpha():
print "Welcome %s " %(yname)
else:
if yname == yname.isdigit():
print ("Name must be alphabetical only!")
yname = raw_input('Enter Name:').isalpha()
This while loop goes on forever, as well as I tried (-) and (+) the raw input variable as I've seen in some tutorials. So I thought of using while loop.
name = raw_input("your name"):
while True:
if name > 0 and name.isalpha():
print "Hi %s " %name
elif name < 0 and name.isdigit():
print "Name must be Alphabet characters only!"
try:
name != name.isalpha():
except (ValueError):
print "Something went wrong"
This will check for both alphabet in the raw_input and check for the length of the name as I see you tried to do in your last try.
import string
import re
name = re.compile(r'[a-zA-Z]+') #This will check for alphabet.
yname = raw_input("Your Name:") #ask the user for input.
while not name.match(yname):
print "invalid characters"
yname = raw_input("Your Name:")
if 5<=len(yname)<=10:
print "Hi,", yname, "!"
elif len(yname)>10:
print "too long!"
elif len(yname)<5:
print "too short!"
You can rearrange your last attempt a bit to get what you want:
while True:
name = raw_input("your name") # ask inside the loop
if name and name.isalpha():
print "Hi %s " %name
break # leave the loop if done
elif name and name.isdigit():
print "Name must be Alphabet characters only!"
else:
print "Please enter something"
Note that if name will be True if name != "".
name = raw_input('Enter your name: ')
while not name.isalpha():
print 'Invaid characters in name'
name = raw_input('Enter your name: ')
Use regexes:
import re
regex = re.compile("^[a-zA-Z]+$")
valid_name = False
while not valid_name:
user_name = raw_input("EnterName")
if not regex.search(user_name):
print "this can't be your name"
else:
print "Hi there, {0}".format(user_name)
valid_name = True
Also, please take note that programmers often make false assumptions about human names
Edit: as an alternative you can skip compiling a regex and just use the pattern in place:
if not re.search("^[a-zA-Z]+$", user_name):
...
However, since you're doing it in a loop compiled version would have slightly better performance, since re.search actually compiles a regex behind the scenes each time invoked.
Also, please note I've changed match to search and slightly modified a regex since there're some differences and it appears tome me that search suits your situation more.
I have already posted a question today and it had 2 problems on it. One of which was solved perfectly, then it got a little complicated. So forgive me but I am posting the other question separately as it confused some peeps:
I am new to python so apologies in advance. Any help is much appreciated. I have been stuck on this code for 2weeks now and I have tunnel vision and cannot work it out:
Basically our assignment was to get to grips with Object-Oriented Programming. We unfortunately have to use "get" and "set" which I've learnt a lot of people dislike, however, as per our tutor we have to do it like that. We were told tp create a program whereby the user is presented with a screen with 3 options. 1. adding a student. 2. viewing a student and 3. removing a student.. within my AddStudent function I have to ask the user to enter fname Lname age degree studying id number (these are the easy bits) and also module name and grade for each module, I have managed to create a loop whereby it will ask the user over and over to enter modules and corresponding grades and will break from said loop when the user enters -1 into the modulname field. However, when trying saving it to a list named students[] ... (which is at the very top of my code above all functions, to apparently make it global) it saves all input from the user re: age name etc but when it comes to saving module names and grades it only saves the last input and not the multiple inputs I need it to. I am unsure if it is within my AddStudent function where it isn't saving or within my ViewStudent function: Both are below (remember I HAVE to use the GET and SET malarky) ;)
students[] # Global List
def addStudent():
print
print "Adding student..."
student = Student()
firstName = raw_input("Please enter the student's first name: ")
lastName = raw_input("Please enter the student's last name: ")
degree = raw_input("Please enter the name of the degree the student is studying: ")
studentid = raw_input("Please enter the students ID number: ")
age = raw_input("Please enter the students Age: ")
while True:
moduleName = raw_input("Please enter module name: ")
if moduleName == "-1":
break
grade = raw_input ("Please enter students grade for " + moduleName+": ")
student.setFirstName(firstName) # Set this student's first name
student.setLastName(lastName)
student.setDegree(degree)# Set this student's last name
student.setGrade(grade)
student.setModuleName(moduleName)
student.setStudentID(studentid)
student.setAge(age)
students.append(student)
print "The student",firstName+' '+lastName,"ID number",studentid,"has been added to the system."
........................
def viewStudent():
print "Printing all students in database : "
for person in students:
print "Printing details for: " + person.getFirstName()+" "+ person.getLastName()
print "Age: " + person.getAge()
print "Student ID: " + person.getStudentID()
print "Degree: " + person.getDegree()
print "Module: " + person.getModuleName()
print "Grades: " + person.getGrade()
your problem is that the module is a single variable you keep changing. instead, make it a list.
while True:
moduleName = raw_input("Please enter module name: ")
if moduleName == "-1":
break
grade = raw_input ("Please enter students grade for " + moduleName+": ")
should be something like
modules = []
while True:
moduleName = raw_input("Please enter module name: ")
if moduleName == "-1":
break
grade = raw_input ("Please enter students grade for " + moduleName+": ")
modules.append((moduleName, grade))
add a new variable to student which is "Modules" and is a list.
and then modules will be a list of tuples which are (moduleName, grade) and to display them, change the line in viewstudent from:
print "Module: " + person.getModuleName()
print "Grades: " + person.getGrade()
to:
for module, grade in person.getModules():
print "Module: " + module
print "Grades: " + grade
It seems you need something like this:
modules = {}
while True:
module_name = raw_input("Please enter module name: ")
if module_name:
grade = raw_input ("Please enter students grade for " + module_name +": ")
modules[module_name] = grade
Modules is a dictionary ("hash map" in other languages), each mod name is key and grades are values, or you could also do it with tuples, wherever floats your boat.
Instead of checking for -1 as a stop condition you check if is true, in python anything empty is evaluated to false.