I have an input file named 'freq' which contains the following data
123 0
133 3
146 1
200 0
233 10
400 2
Now I've attempted to write a script that would take a number from the
standard input and then
have the program return the number in the input file that is closest
to that input file.
#!/usr/local/bin/python
import sys
def construct_set(data):
for line in data:
lines = line.splitlines()
for curline in lines:
if curline.strip():
key = curline.split(' ')
value = int(key[0])
yield value
def approximate(first, second):
midpoint = (first + second) / 2
return midpoint
def format(input):
prev = 0
value = int(input)
with open("/home/cdalten/oakland/freq") as f:
for next in construct_set(f):
if value > prev:
current = prev
prev = next
middle = approximate(current, prev)
if middle < prev and value > middle:
return prev
elif value > current and current < middle:
return current
if __name__ == "__main__":
if len(sys.argv) != 2:
print >> sys.stderr, "You need to enter a number\n"
sys.exit(1)
nearest = format(sys.argv[1])
print "The closest value to", sys.argv[1], "is", nearest
When I run it, I get the following...
[cdal...@localhost oakland]$ ./android4.py 123
The closest value to 123 is 123
[cdal...@localhost oakland]$ ./android4.py 130
The closest value to 130 is 133
[cdal...@localhost oakland]$ ./android4.py 140
The closest value to 140 is 146
[cdal...@localhost oakland]$ ./android4.py 146
The closest value to 146 is 146
[cdal...@localhost oakland]$ ./android4.py 190
The closest value to 190 is 200
[cdal...@localhost oakland]$ ./android4.py 200
The closest value to 200 is 200
[cdal...@localhost oakland]$ ./android4.py 205
The closest value to 205 is 200
[cdal...@localhost oakland]$ ./android4.py 210
The closest value to 210 is 200
[cdal...@localhost oakland]$ ./android4.py 300
The closest value to 300 is 233
[cdal...@localhost oakland]$ ./android4.py 500
The closest value to 500 is 400
[cdal...@localhost oakland]$ ./android4.py 1000000
The closest value to 1000000 is 400
[cdal...@localhost oakland]$
The question is about the construct_set() function.
def construct_set(data):
for line in data:
lines = line.splitlines()
for curline in lines:
if curline.strip():
key = curline.split(' ')
value = int(key[0])
yield value
I have it yield on 'value' instead of 'curline'. Will the program
still read the input file named freq line by line even though I don't
have it yielding on 'curline'? Or since I have it yield on 'value',
will it read the entire input file into memory at once?
Chad
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