How to count the number of sub-sequences in a string?
This program is to count the number of sub-strings in a string.
Test case:
string ABCDCDC
pattern CDC
The answer should be 2 but I am getting 0.
def count_substring(string, sub_string):
for i in range(0,len(string)-len(sub_string)+1):
count=0
for j in range(0,len(sub_string)):
if(string[i+j]!=sub_string[j]):
break;
if j==len(sub_string):
count=count+1
return count
python string substring
edited Nov 21 '18 at 1:28
martineau
68.9k1091186
add a comment |
This program is to count the number of sub-strings in a string.
Test case:
string ABCDCDC
pattern CDC
The answer should be 2 but I am getting 0.
def count_substring(string, sub_string):
for i in range(0,len(string)-len(sub_string)+1):
count=0
for j in range(0,len(sub_string)):
if(string[i+j]!=sub_string[j]):
break;
if j==len(sub_string):
count=count+1
return count
python string substring
edited Nov 21 '18 at 1:28
martineau
68.9k1091186
Make sure your indentation is correct when you post...
– Julien
Nov 21 '18 at 0:05
add a comment |
This program is to count the number of sub-strings in a string.
Test case:
string ABCDCDC
pattern CDC
The answer should be 2 but I am getting 0.
def count_substring(string, sub_string):
for i in range(0,len(string)-len(sub_string)+1):
count=0
for j in range(0,len(sub_string)):
if(string[i+j]!=sub_string[j]):
break;
if j==len(sub_string):
count=count+1
return count
python string substring
edited Nov 21 '18 at 1:28
martineau
68.9k1091186
This program is to count the number of sub-strings in a string.
Test case:
string ABCDCDC
pattern CDC
The answer should be 2 but I am getting 0.
def count_substring(string, sub_string):
for i in range(0,len(string)-len(sub_string)+1):
count=0
for j in range(0,len(sub_string)):
if(string[i+j]!=sub_string[j]):
break;
if j==len(sub_string):
count=count+1
return count
python string substring
python string substring
edited Nov 21 '18 at 1:28
martineau
68.9k1091186
edited Nov 21 '18 at 1:28
martineau
68.9k1091186
edited Nov 21 '18 at 1:28
martineau
68.9k1091186
edited Nov 21 '18 at 1:28
martineau
68.9k1091186
edited Nov 21 '18 at 1:28
martineau
68.9k1091186
68.9k1091186
asked Nov 20 '18 at 23:43
user10628441
Make sure your indentation is correct when you post...
– Julien
Nov 21 '18 at 0:05
add a comment |
Make sure your indentation is correct when you post...
– Julien
Nov 21 '18 at 0:05
Make sure your indentation is correct when you post...
– Julien
Nov 21 '18 at 0:05
Make sure your indentation is correct when you post...
– Julien
Nov 21 '18 at 0:05
add a comment |
2 Answers
2
active
oldest
votes
At the end of the for j in range(0,len(sub_string)) loop j can be at most len(sub_string)-1 (if you don't break early). So if j==len(sub_string): is always False. You want if j==len(sub_string)-1: or simply else: (meaning you've reached the end of the for loop) instead.
Also count = 0 should be initialized at the start, not in the first for loop:
def count_substring(string, sub_string):
count=0
for i in range(0,len(string)-len(sub_string)+1):
for j in range(0,len(sub_string)):
if(string[i+j]!=sub_string[j]):
break;
else:
count=count+1
return count
answered Nov 20 '18 at 23:56
JulienJulien
7,69831637
add a comment |
Strings are sequences of 1-character substrings in Python, so you can use the built-in count() method — in other words, you don't have to re-invent the wheel and write your own function to do it.
test_string = 'ABCDCDC'
sub_string = 'CDC'
print(test_string.count(sub_string)) # -> 2
answered Nov 21 '18 at 1:20
martineaumartineau
68.9k1091186
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
At the end of the for j in range(0,len(sub_string)) loop j can be at most len(sub_string)-1 (if you don't break early). So if j==len(sub_string): is always False. You want if j==len(sub_string)-1: or simply else: (meaning you've reached the end of the for loop) instead.
Also count = 0 should be initialized at the start, not in the first for loop:
def count_substring(string, sub_string):
count=0
for i in range(0,len(string)-len(sub_string)+1):
for j in range(0,len(sub_string)):
if(string[i+j]!=sub_string[j]):
break;
else:
count=count+1
return count
answered Nov 20 '18 at 23:56
JulienJulien
7,69831637
add a comment |
At the end of the for j in range(0,len(sub_string)) loop j can be at most len(sub_string)-1 (if you don't break early). So if j==len(sub_string): is always False. You want if j==len(sub_string)-1: or simply else: (meaning you've reached the end of the for loop) instead.
Also count = 0 should be initialized at the start, not in the first for loop:
def count_substring(string, sub_string):
count=0
for i in range(0,len(string)-len(sub_string)+1):
for j in range(0,len(sub_string)):
if(string[i+j]!=sub_string[j]):
break;
else:
count=count+1
return count
answered Nov 20 '18 at 23:56
JulienJulien
7,69831637
add a comment |
At the end of the for j in range(0,len(sub_string)) loop j can be at most len(sub_string)-1 (if you don't break early). So if j==len(sub_string): is always False. You want if j==len(sub_string)-1: or simply else: (meaning you've reached the end of the for loop) instead.
Also count = 0 should be initialized at the start, not in the first for loop:
def count_substring(string, sub_string):
count=0
for i in range(0,len(string)-len(sub_string)+1):
for j in range(0,len(sub_string)):
if(string[i+j]!=sub_string[j]):
break;
else:
count=count+1
return count
answered Nov 20 '18 at 23:56
JulienJulien
7,69831637
At the end of the for j in range(0,len(sub_string)) loop j can be at most len(sub_string)-1 (if you don't break early). So if j==len(sub_string): is always False. You want if j==len(sub_string)-1: or simply else: (meaning you've reached the end of the for loop) instead.
Also count = 0 should be initialized at the start, not in the first for loop:
def count_substring(string, sub_string):
count=0
for i in range(0,len(string)-len(sub_string)+1):
for j in range(0,len(sub_string)):
if(string[i+j]!=sub_string[j]):
break;
else:
count=count+1
return count
answered Nov 20 '18 at 23:56
JulienJulien
7,69831637
answered Nov 20 '18 at 23:56
JulienJulien
7,69831637
answered Nov 20 '18 at 23:56
JulienJulien
7,69831637
answered Nov 20 '18 at 23:56
JulienJulien
7,69831637
7,69831637
add a comment |
add a comment |
Strings are sequences of 1-character substrings in Python, so you can use the built-in count() method — in other words, you don't have to re-invent the wheel and write your own function to do it.
test_string = 'ABCDCDC'
sub_string = 'CDC'
print(test_string.count(sub_string)) # -> 2
answered Nov 21 '18 at 1:20
martineaumartineau
68.9k1091186
add a comment |
Strings are sequences of 1-character substrings in Python, so you can use the built-in count() method — in other words, you don't have to re-invent the wheel and write your own function to do it.
test_string = 'ABCDCDC'
sub_string = 'CDC'
print(test_string.count(sub_string)) # -> 2
answered Nov 21 '18 at 1:20
martineaumartineau
68.9k1091186
add a comment |
Strings are sequences of 1-character substrings in Python, so you can use the built-in count() method — in other words, you don't have to re-invent the wheel and write your own function to do it.
test_string = 'ABCDCDC'
sub_string = 'CDC'
print(test_string.count(sub_string)) # -> 2
answered Nov 21 '18 at 1:20
martineaumartineau
68.9k1091186
Strings are sequences of 1-character substrings in Python, so you can use the built-in count() method — in other words, you don't have to re-invent the wheel and write your own function to do it.
test_string = 'ABCDCDC'
sub_string = 'CDC'
print(test_string.count(sub_string)) # -> 2
answered Nov 21 '18 at 1:20
martineaumartineau
68.9k1091186
answered Nov 21 '18 at 1:20
martineaumartineau
68.9k1091186
answered Nov 21 '18 at 1:20
martineaumartineau
68.9k1091186
answered Nov 21 '18 at 1:20
martineaumartineau
68.9k1091186
68.9k1091186
add a comment |
add a comment |
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Make sure your indentation is correct when you post...
– Julien
Nov 21 '18 at 0:05