New to python, what am i doing wrong here that it wont print my total out?
second = 2
third = 3
extra = input("what is the extra value?")
total = ("first+second+thrid+extra")
print("total,")
You are printing a string by putting in double quotes
Whereas expression should be like this:
result = first + second + extra
print(result) # without quotes
Related
string = "6+324-909+5+55-1"
listPositive = []
listNegative = []
I would like to put numbers with "+" in front of them in listPositive and numbers with "-" in front of them in listNegative. Just the numbers without operators, but using the operators for distinction. I have managed to find a way to seperate the first number which has neither plus nor minus in front of it.
I am very very green and I will gladly hear about different ways to go about it or even suggestions for a whole different line of thinking.
I tried:
s1='678-6783742+2342+4-8'
lst=s1.split()
sample=[]
for i in lst:
if '-' in i:
sample.append(i[1:])
print(sample)
And was expecting:
['6783742', '8']
But it only worked that way when I put spaces in like this:
s1='678 -6783742 +2342 +4 -8'
In your question you already have the answer: replace- with - and + with + (note the space before operator) and then split:
s = "678-6783742+2342+4-8"
s = s.replace("+", " +").replace("-", " -")
negative = []
for i in s.split():
if i.startswith("-"):
negative.append(i[1:])
print(negative)
Prints:
['6783742', '8']
I am trying to iterate over some integer values and insert them into an string which has to be in a weird format to work. The exact output (including the outer quotes) I need if the value was 64015 would be:
"param={\"zip\":\"64015\"}"
I have tried f string formatting but couldn't get it to work. It has problem with the backslashes and when I escaped them the output was not exactly like above string
Hopefully, I made myself clear enough.
You would have to escape the backslash and the double quotes seperately like this:
string = '"param={\\\"zip\\\":\\\"' + str(64015) + '\\\"}"'
The result of this is:
"param={\"zip\":\"64015\"}"
You can use alternate ways to delimit the outer string ('...', '''...''', """...""") or use str.format() or old style %-formatting syntax to get there (see f-style workaround at the end):
s = s = 'param={"zip":"' + str(64015) + '"}'
print(s)
s = '''param={"zip":"''' + str(64015) +'''"}'''
print(s)
s = """param={"zip":"64015"}""" # not suited for variable replacement
print(s)
s = 'param={{"zip":"{0}"}}'.format(64015)
print(s)
s = 'param={"zip":"%s"}' % 64015
print(s)
Output:
param={"zip":"64015"}
param={"zip":"64015"}
param={"zip":"64015"}
param={"zip":"64015"}
If you need any "\" in there simply drop a \\ in:
s = '"param={\\"zip\\":\\"' + str(64015) + '\\"}"'
print(s)
s = '''"param={\\"zip\\":\\"''' + str(64015) +'''\\"}"'''
print(s)
s = '"param={{\\"zip\\":\\"{0}\\"}}"'.format(64015)
print(s)
s = '"param={\\"zip\\":\\"%s\\"}"' % 64015
print(s)
Output:
"param={\"zip\":\"64015\"}"
"param={\"zip\":\"64015\"}"
"param={\"zip\":\"64015\"}"
"param={\"zip\":\"64015\"}"
The f-string workaround variant would look like so:
a = '\\"'
num = 64015
s = f'"param={{{a}zip{a}:{a}{num}{a}}}"'
and if printed also yields :
"param={\"zip\":\"64015\"}"
More on the topic can be found here: 'Custom string formatting' on python.org
I played around a bit with f-strings and .format() but ultimately got this to work:
foo = 90210
bar = '"param={\\"zip\\":\\"%s\\"}"' % (foo)
print(bar)
giving:
"param={\"zip\":\"90210\"}"
Hopefully someone can give you an f-string alternative. I kept running into unallowed "\" in my f-string attempts.
Is it only this?
a = "param={\"zip\":\"64015\"}"
b = a.split('=')
c = eval(b[1])
print(c)
print(c['zip'])
Result:
{'zip': '64015'}
64015
Please note that evaluating (eval()) strings from unknown source may
be dangerous! It may run the code that you are not expecting.
First question here.
I am picking up Python and have a question that may be quite basic.
I am trying to create this pattern with a nested loop:
x
x
x
xxx
With the code:
numbers = [1,1,1,3]
for count_x in numbers:
output = ""
for count in range(count_x):
output +=x
print(output)
My question is - why does my output change when I move the position of print(output).
The code above works but when I align print(output) with the for count_x in numbers:, I only get "xxx", when I align print(output) to output +=x, I get the following:
x
x
x
x
xx
xxx
which is very odd because there are only 4 items in the list and it shows me 6 lines of output.
Could someone please help? Really puzzled. Thank yall very much.
There's a difference between these two bits of code (fixing the x/"x" problem along the way - your code won't actually work as is unless you have a variable x):
# First:
numbers = [1,1,1,3]
for count_x in numbers:
output = ""
for count in range(count_x):
output += "x"
print(output)
# Second:
numbers = [1,1,1,3]
for count_x in numbers:
output = ""
for count in range(count_x):
output += "x"
print(output)
In the second, the print is done inside the loop that creates the string, meaning you print it out multiple times while building it. That's where your final three lines come from: *, ** and ***. This doesn't matter for all the previous lines since there's no functional difference. Printing a one character string at the end or after adding each of the one characters has the same effect.
In the first, you only print the string after fully constructing it.
You can see this effect by using a slightly modified version that outputs different things for each outer loop:
numbers = [1,1,1,3]
x = 1
for count_x in numbers:
output = ""
for count in range(count_x):
output += str(x)
print(output)
x += 1
This shows that the final three lines are part of a single string construction (comments added):
1 \
2 >- | Each is one outer/inner loop.
3 /
4 \ | A single outer loop, printing
44 >- | string under construction for
444 / | each inner loop.
In any case, there are better ways to do what you want, such as:
numbers = [1,1,1,3]
for count_x in numbers:
print('x' * count_x)
You could probably also do it on one line with a list comprehension but that's probably overkill.
I'm trying to figure out how to print a one line string while using a for loop. If there are other ways that you know of, I would appreciate the help. Thank you. Also, try edit off my code!
times = int(input("Enter a number: "))
print(times)
a = 0
for i in range(times+1):
print("*"*i)
a += i
print("Total stars: ")
print(a)
print("Equation: ")
for e in range(1,times+1):
print(e)
if e != times:
print("+")
else:
pass
Out:
Enter a number: 5
*
**
***
****
*****
Equation:
1
+
2
+
3
+
4
+
5
How do I make the equation in just one single line like this:
1+2+3+4+5
I don't think you can do a "backspace" after you've printed. At least erasing from the terminal isn't going to be done very easily. But you can build the string before you print it:
times = int(input("Enter a number: "))
print(times)
a = 0
for i in range(times+1):
print("*"*i)
a += i
print("Total stars: ")
print(a)
print("Equation: ")
equation_string = ""
for e in range(1,times+1):
equation_string += str(e)
if e != times:
equation_string += "+"
else:
pass
print(equation_string)
Basically, what happens is you store the temporary equation in equation_str so it's built like this:
1
1+
1+2
1+2+
...
And then you print equation_str once it's completely built. The output of the modified program is this
Enter a number: 5
5
*
**
***
****
*****
Total stars:
15
Equation:
1+2+3+4+5
Feel free to post a comment if anything is unclear.
Instead of your original for loop to print each number, try this:
output = '+'.join([str(i) for i in range(1, times + 1)])
print(output)
Explanation:
[str(i) for i in range(1, times + 1)] is a list comprehension that returns a list of all your numbers, converted to strings so that we can print them.
'+'.join(...) joins each element of your list, with a + in between each element.
Alternatively:
If you want a simple modification to your original code, you can simply suppress the newline from each print statement with the keyword paramater end, and set this to an empty string:
print(e, end='')
(Note that I am addressed the implied question, not the 'how do I do a backspace' question)
Too long for a comment, so I will post here.
The formatting options of python can come into good use, if you have a sequence you wish to format and print.
Consider the following...
>>> num = 5 # number of numbers to generate
>>> n = num-1 # one less used in generating format string
>>> times = [i for i in range(1,num+1)] # generate your numbers
>>> ("{}+"*n + "{}=").format(*times) # format your outputs
'1+2+3+4+5='
So although this doesn't answer your question, you can see that list comprehensions can be brought into play to generate your list of values, which can then be used in the format generation. The format string can also be produced with a l.c. but it gets pretty messy when you want to incorporate string elements like the + and = as shown in the above example.
I think you are looking for the end parameter for the print function - i.e. print(e, end='') which prints each value of e as it arrives followed by no space or newline.
I am beginning to learn python and want to cut a string at the spaces; so 'hello world' becomes 'hello' and 'world'. To do this i want to save the locations of the spaces in a list, but i can't figure out how to do this. In order to find the spaces i do this:
def string_splitting(text):
i = 0
for i in range(len(text)):
if (text[i]==' '):
After saving them in the list i want to display them with text[:list[1]] (or something like that)
Can anyone help me with the saving it in a list part; and is this even possible?
(Another way to cut the string is welcome to :-) )
Thanks.
Use split:
"hello world my name is".split(' ')
It will give you a list of strings
thanks, i tried to do it without the split option, should have said that in the question..
anyways this worked;
def split_stringj(text):
a = text.count(' ')
p = len(text)
l = [-1]
x = 0
y = 1
for x in range(p):
if (text[x]==' '):
l.append(x)
y += 1
l.append(p)
print l
for x in range(len(l)-1):
print text[l[x]+1:l[x+1]]