File name with special character “^” unrecognized by pattern.match (RegEx function)

I'm working with Python 3.6.5 on a Winows 10.

I can not verify if a file exists in a directory or not.
The problem seems to come from the special character "^".

When I run the code below, the "WITHOUT_CIRCUMFLEX" and "^WITH_CIRCUMFLEX" files are well listed by the os.listdir () function.
However, the file "^ WITH_CIRCUMFLEX" is not recognized by the function pattern.match (file) ... while it exists!

Would anyone have an idea to solve this problem?
Thanks for your help

# coding: utf-8



import pandas as pd

import os.path

import regex

path = "C:UsersDavidtest"

list_name = ['WITHOUT_CIRCUMFLEX', '^WITH_CIRCUMFLEX']




df_empty = pd.DataFrame()




for name in list_name:

    df_empty.to_pickle('{path}{name}.pkl'.format(**locals()))

    pattern = regex.compile('{name}.pkl'.format(**locals()))




# Check if file already exist

check = False

for file in os.listdir(path):

    print("I found this filet" + file)

    if pattern.match(file):

        check = True



if check is True:

    print("t" + name + " file exist" + "n")

else:

    print("t" + name + " does not exist")

asked Nov 25 '18 at 9:58

David

214

What's the regex module? I think your meaning is import re. And ^ is a metacharacter. You have to use ^.

– user7121223
Nov 25 '18 at 10:04

Python has an inbuilt regex module, but the name is "re". to use it, type import re. I have not seen the import regex statement before.

– Paritosh Singh
Nov 25 '18 at 10:05

^ is a regex meta character, meaning "match at the start of the string". You'd need to escape it if you wanted to use it in a regex.

– Martijn Pieters♦
Nov 25 '18 at 10:06

Why use a regex for this though? Are you looking for files that end in {name}.pkl, or files that consist entirely of {name}.pkl? Neither match requires a regex.

– Martijn Pieters♦
Nov 25 '18 at 10:11

1

@ParitoshSingh: there are legitimate uses for the regex module. I don't see those here, but it could very well be intentional.

– Martijn Pieters♦
Nov 25 '18 at 10:12

|
show 2 more comments

I'm working with Python 3.6.5 on a Winows 10.

I can not verify if a file exists in a directory or not.
The problem seems to come from the special character "^".

Would anyone have an idea to solve this problem?
Thanks for your help

# coding: utf-8



import pandas as pd

import os.path

import regex

path = "C:UsersDavidtest"

list_name = ['WITHOUT_CIRCUMFLEX', '^WITH_CIRCUMFLEX']




df_empty = pd.DataFrame()




for name in list_name:

    df_empty.to_pickle('{path}{name}.pkl'.format(**locals()))

    pattern = regex.compile('{name}.pkl'.format(**locals()))




# Check if file already exist

check = False

for file in os.listdir(path):

    print("I found this filet" + file)

    if pattern.match(file):

        check = True



if check is True:

    print("t" + name + " file exist" + "n")

else:

    print("t" + name + " does not exist")

asked Nov 25 '18 at 9:58

David

214

What's the regex module? I think your meaning is import re. And ^ is a metacharacter. You have to use ^.

– user7121223
Nov 25 '18 at 10:04

Python has an inbuilt regex module, but the name is "re". to use it, type import re. I have not seen the import regex statement before.

– Paritosh Singh
Nov 25 '18 at 10:05

^ is a regex meta character, meaning "match at the start of the string". You'd need to escape it if you wanted to use it in a regex.

– Martijn Pieters♦
Nov 25 '18 at 10:06

Why use a regex for this though? Are you looking for files that end in {name}.pkl, or files that consist entirely of {name}.pkl? Neither match requires a regex.

– Martijn Pieters♦
Nov 25 '18 at 10:11

1

@ParitoshSingh: there are legitimate uses for the regex module. I don't see those here, but it could very well be intentional.

– Martijn Pieters♦
Nov 25 '18 at 10:12

|
show 2 more comments

I'm working with Python 3.6.5 on a Winows 10.

I can not verify if a file exists in a directory or not.
The problem seems to come from the special character "^".

Would anyone have an idea to solve this problem?
Thanks for your help

# coding: utf-8



import pandas as pd

import os.path

import regex

path = "C:UsersDavidtest"

list_name = ['WITHOUT_CIRCUMFLEX', '^WITH_CIRCUMFLEX']




df_empty = pd.DataFrame()




for name in list_name:

    df_empty.to_pickle('{path}{name}.pkl'.format(**locals()))

    pattern = regex.compile('{name}.pkl'.format(**locals()))




# Check if file already exist

check = False

for file in os.listdir(path):

    print("I found this filet" + file)

    if pattern.match(file):

        check = True



if check is True:

    print("t" + name + " file exist" + "n")

else:

    print("t" + name + " does not exist")

asked Nov 25 '18 at 9:58

David

214

I'm working with Python 3.6.5 on a Winows 10.

I can not verify if a file exists in a directory or not.
The problem seems to come from the special character "^".

Would anyone have an idea to solve this problem?
Thanks for your help

# coding: utf-8



import pandas as pd

import os.path

import regex

path = "C:UsersDavidtest"

list_name = ['WITHOUT_CIRCUMFLEX', '^WITH_CIRCUMFLEX']




df_empty = pd.DataFrame()




for name in list_name:

    df_empty.to_pickle('{path}{name}.pkl'.format(**locals()))

    pattern = regex.compile('{name}.pkl'.format(**locals()))




# Check if file already exist

check = False

for file in os.listdir(path):

    print("I found this filet" + file)

    if pattern.match(file):

        check = True



if check is True:

    print("t" + name + " file exist" + "n")

else:

    print("t" + name + " does not exist")

python regex utf-8

asked Nov 25 '18 at 9:58

David

214

asked Nov 25 '18 at 9:58

David

214

asked Nov 25 '18 at 9:58

David

214

asked Nov 25 '18 at 9:58

David

214

asked Nov 25 '18 at 9:58

David

214

What's the regex module? I think your meaning is import re. And ^ is a metacharacter. You have to use ^.

– user7121223
Nov 25 '18 at 10:04

Python has an inbuilt regex module, but the name is "re". to use it, type import re. I have not seen the import regex statement before.

– Paritosh Singh
Nov 25 '18 at 10:05

^ is a regex meta character, meaning "match at the start of the string". You'd need to escape it if you wanted to use it in a regex.

– Martijn Pieters♦
Nov 25 '18 at 10:06

Why use a regex for this though? Are you looking for files that end in {name}.pkl, or files that consist entirely of {name}.pkl? Neither match requires a regex.

– Martijn Pieters♦
Nov 25 '18 at 10:11

1

@ParitoshSingh: there are legitimate uses for the regex module. I don't see those here, but it could very well be intentional.

– Martijn Pieters♦
Nov 25 '18 at 10:12

|
show 2 more comments

What's the regex module? I think your meaning is import re. And ^ is a metacharacter. You have to use ^.

– user7121223
Nov 25 '18 at 10:04

Python has an inbuilt regex module, but the name is "re". to use it, type import re. I have not seen the import regex statement before.

– Paritosh Singh
Nov 25 '18 at 10:05

^ is a regex meta character, meaning "match at the start of the string". You'd need to escape it if you wanted to use it in a regex.

– Martijn Pieters♦
Nov 25 '18 at 10:06

Why use a regex for this though? Are you looking for files that end in {name}.pkl, or files that consist entirely of {name}.pkl? Neither match requires a regex.

– Martijn Pieters♦
Nov 25 '18 at 10:11

1

@ParitoshSingh: there are legitimate uses for the regex module. I don't see those here, but it could very well be intentional.

– Martijn Pieters♦
Nov 25 '18 at 10:12

What's the regex module? I think your meaning is import re. And ^ is a metacharacter. You have to use ^.

– user7121223
Nov 25 '18 at 10:04

Python has an inbuilt regex module, but the name is "re". to use it, type import re. I have not seen the import regex statement before.

– Paritosh Singh
Nov 25 '18 at 10:05

^ is a regex meta character, meaning "match at the start of the string". You'd need to escape it if you wanted to use it in a regex.

– Martijn Pieters♦
Nov 25 '18 at 10:06

Why use a regex for this though? Are you looking for files that end in {name}.pkl, or files that consist entirely of {name}.pkl? Neither match requires a regex.

– Martijn Pieters♦
Nov 25 '18 at 10:11

@ParitoshSingh: there are legitimate uses for the regex module. I don't see those here, but it could very well be intentional.

– Martijn Pieters♦
Nov 25 '18 at 10:12

|
show 2 more comments

2 Answers
2

active

oldest

votes

^ is a regex meta character, so it'll not match a literal ^ character in text. You'd need to escape such characters:

'^WITH_CIRCUMFLEX'

If your inputs are generated or taken from another source, use the regex.escape() function to escape meta characters for you:

for name in list_name:

    df_empty.to_pickle('{path}{name}.pkl'.format(**locals()))

    name = regex.escape(name, special_only=True)

    pattern = regex.compile('{name}.pkl'.format(**locals()))

However, if you are looking to match files, you currently are not using any of the reasons you'd use a regular expression. Your pattern will at best match any filename that ends with {name}.pkl. You'd be much better off using the glob module:

import glob



for name in list_name:

    ...

    escaped_name = glob.escape(name)

    files = glob.glob('*{}.pkl'.format(escaped_name))

edited Nov 25 '18 at 10:28

answered Nov 25 '18 at 10:09

Martijn Pieters♦

715k13724952308

Thanks a lot, it works perfectly with your regex.escape function solution :-)

– David
Nov 26 '18 at 15:22

add a comment |

^ is a regex metacharacter, so you have to escape it. The easiest way to do this is to use the regex.escape function, which automatically escapes metacharacters in an arbitrary string.

So instead of

pattern = regex.compile('{name}.pkl'.format(**locals()))

use

pattern = regex.compile(regex.escape('{name}.pkl').format(**locals()))

edited Nov 25 '18 at 10:13

answered Nov 25 '18 at 10:11

Tomothy32

7,0731626

regex is the next-generation version, installable from PyPI: pypi.org/project/regex

– Martijn Pieters♦
Nov 25 '18 at 10:12

Not that they are using the features of the library here.

– Martijn Pieters♦
Nov 25 '18 at 10:12

Didn't know that, I'll change my answer. Thanks!

– Tomothy32
Nov 25 '18 at 10:13

add a comment |

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2 Answers
2

active

oldest

votes

2 Answers
2

active

oldest

votes

^ is a regex meta character, so it'll not match a literal ^ character in text. You'd need to escape such characters:

'^WITH_CIRCUMFLEX'

If your inputs are generated or taken from another source, use the regex.escape() function to escape meta characters for you:

for name in list_name:

    df_empty.to_pickle('{path}{name}.pkl'.format(**locals()))

    name = regex.escape(name, special_only=True)

    pattern = regex.compile('{name}.pkl'.format(**locals()))

import glob



for name in list_name:

    ...

    escaped_name = glob.escape(name)

    files = glob.glob('*{}.pkl'.format(escaped_name))

edited Nov 25 '18 at 10:28

answered Nov 25 '18 at 10:09

Martijn Pieters♦

715k13724952308

Thanks a lot, it works perfectly with your regex.escape function solution :-)

– David
Nov 26 '18 at 15:22

add a comment |

^ is a regex meta character, so it'll not match a literal ^ character in text. You'd need to escape such characters:

'^WITH_CIRCUMFLEX'

If your inputs are generated or taken from another source, use the regex.escape() function to escape meta characters for you:

for name in list_name:

    df_empty.to_pickle('{path}{name}.pkl'.format(**locals()))

    name = regex.escape(name, special_only=True)

    pattern = regex.compile('{name}.pkl'.format(**locals()))

import glob



for name in list_name:

    ...

    escaped_name = glob.escape(name)

    files = glob.glob('*{}.pkl'.format(escaped_name))

edited Nov 25 '18 at 10:28

answered Nov 25 '18 at 10:09

Martijn Pieters♦

715k13724952308

Thanks a lot, it works perfectly with your regex.escape function solution :-)

– David
Nov 26 '18 at 15:22

add a comment |

^ is a regex meta character, so it'll not match a literal ^ character in text. You'd need to escape such characters:

'^WITH_CIRCUMFLEX'

If your inputs are generated or taken from another source, use the regex.escape() function to escape meta characters for you:

for name in list_name:

    df_empty.to_pickle('{path}{name}.pkl'.format(**locals()))

    name = regex.escape(name, special_only=True)

    pattern = regex.compile('{name}.pkl'.format(**locals()))

import glob



for name in list_name:

    ...

    escaped_name = glob.escape(name)

    files = glob.glob('*{}.pkl'.format(escaped_name))

edited Nov 25 '18 at 10:28

answered Nov 25 '18 at 10:09

Martijn Pieters♦

715k13724952308

^ is a regex meta character, so it'll not match a literal ^ character in text. You'd need to escape such characters:

'^WITH_CIRCUMFLEX'

If your inputs are generated or taken from another source, use the regex.escape() function to escape meta characters for you:

for name in list_name:

    df_empty.to_pickle('{path}{name}.pkl'.format(**locals()))

    name = regex.escape(name, special_only=True)

    pattern = regex.compile('{name}.pkl'.format(**locals()))

import glob



for name in list_name:

    ...

    escaped_name = glob.escape(name)

    files = glob.glob('*{}.pkl'.format(escaped_name))

edited Nov 25 '18 at 10:28

answered Nov 25 '18 at 10:09

Martijn Pieters♦

715k13724952308

edited Nov 25 '18 at 10:28

answered Nov 25 '18 at 10:09

Martijn Pieters♦

715k13724952308

answered Nov 25 '18 at 10:09

Martijn Pieters♦

715k13724952308

answered Nov 25 '18 at 10:09

Martijn Pieters♦

715k13724952308

Thanks a lot, it works perfectly with your regex.escape function solution :-)

– David
Nov 26 '18 at 15:22

add a comment |

Thanks a lot, it works perfectly with your regex.escape function solution :-)

– David
Nov 26 '18 at 15:22

Thanks a lot, it works perfectly with your regex.escape function solution :-)

– David
Nov 26 '18 at 15:22

add a comment |

^ is a regex metacharacter, so you have to escape it. The easiest way to do this is to use the regex.escape function, which automatically escapes metacharacters in an arbitrary string.

So instead of

pattern = regex.compile('{name}.pkl'.format(**locals()))

use

pattern = regex.compile(regex.escape('{name}.pkl').format(**locals()))

edited Nov 25 '18 at 10:13

answered Nov 25 '18 at 10:11

Tomothy32

7,0731626

regex is the next-generation version, installable from PyPI: pypi.org/project/regex

– Martijn Pieters♦
Nov 25 '18 at 10:12

Not that they are using the features of the library here.

– Martijn Pieters♦
Nov 25 '18 at 10:12

Didn't know that, I'll change my answer. Thanks!

– Tomothy32
Nov 25 '18 at 10:13

add a comment |

^ is a regex metacharacter, so you have to escape it. The easiest way to do this is to use the regex.escape function, which automatically escapes metacharacters in an arbitrary string.

So instead of

pattern = regex.compile('{name}.pkl'.format(**locals()))

use

pattern = regex.compile(regex.escape('{name}.pkl').format(**locals()))

edited Nov 25 '18 at 10:13

answered Nov 25 '18 at 10:11

Tomothy32

7,0731626

regex is the next-generation version, installable from PyPI: pypi.org/project/regex

– Martijn Pieters♦
Nov 25 '18 at 10:12

Not that they are using the features of the library here.

– Martijn Pieters♦
Nov 25 '18 at 10:12

Didn't know that, I'll change my answer. Thanks!

– Tomothy32
Nov 25 '18 at 10:13

add a comment |

^ is a regex metacharacter, so you have to escape it. The easiest way to do this is to use the regex.escape function, which automatically escapes metacharacters in an arbitrary string.

So instead of

pattern = regex.compile('{name}.pkl'.format(**locals()))

use

pattern = regex.compile(regex.escape('{name}.pkl').format(**locals()))

edited Nov 25 '18 at 10:13

answered Nov 25 '18 at 10:11

Tomothy32

7,0731626

^ is a regex metacharacter, so you have to escape it. The easiest way to do this is to use the regex.escape function, which automatically escapes metacharacters in an arbitrary string.

So instead of

pattern = regex.compile('{name}.pkl'.format(**locals()))

use

pattern = regex.compile(regex.escape('{name}.pkl').format(**locals()))

edited Nov 25 '18 at 10:13

answered Nov 25 '18 at 10:11

Tomothy32

7,0731626

edited Nov 25 '18 at 10:13

answered Nov 25 '18 at 10:11

Tomothy32

7,0731626

answered Nov 25 '18 at 10:11

Tomothy32

7,0731626

answered Nov 25 '18 at 10:11

Tomothy32

7,0731626

regex is the next-generation version, installable from PyPI: pypi.org/project/regex

– Martijn Pieters♦
Nov 25 '18 at 10:12

Not that they are using the features of the library here.

– Martijn Pieters♦
Nov 25 '18 at 10:12

Didn't know that, I'll change my answer. Thanks!

– Tomothy32
Nov 25 '18 at 10:13

add a comment |

regex is the next-generation version, installable from PyPI: pypi.org/project/regex

– Martijn Pieters♦
Nov 25 '18 at 10:12

Not that they are using the features of the library here.

– Martijn Pieters♦
Nov 25 '18 at 10:12

Didn't know that, I'll change my answer. Thanks!

– Tomothy32
Nov 25 '18 at 10:13

regex is the next-generation version, installable from PyPI: pypi.org/project/regex

– Martijn Pieters♦
Nov 25 '18 at 10:12

Not that they are using the features of the library here.

– Martijn Pieters♦
Nov 25 '18 at 10:12

Didn't know that, I'll change my answer. Thanks!

– Tomothy32
Nov 25 '18 at 10:13

add a comment |

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