Regular Expressions 101

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An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

/
/
gm

Test String

Code Generator

Language

Generated Code

# coding=utf8 # the above tag defines encoding for this document and is for Python 2.x compatibility import re regex = r"^(?i)CHOC.*[.csv]$" test_str = ("CHOC_METRICS_2020-06-16.csv\n" "Claims_PGSEO_20200110.txt\n" "Claims_Agilon_20200110.txt\n" "COPC_PE20190701_REHCF.TXT\n" "Member_Agilon_PGSEO_Current_QualityRA_History_20200116.txt\n" "Member_Agilon_PGSEO_Current_QualityRA_20200215.txt\n" "Member_Agilon_PGSEO_Locked_Financial_20200115.txt\n" "Member_Agilon_PGSEO_Locked_Financial_History_20200116.txt\n" "Claims_PGSEO_History_20200116.txt\n" "Member_Agilon_Current_QualityRA_20200215.txt\n" "Member_Agilon_Locked_Financial_20191215.txt\n" "COPC_ME_AETACOE6_201912_20200127.txt\n" "SGPPN_PE20190701_REHCF.TXT\n" "SGPPN_PE20200101_RECLMEXP.TXT\n" "SGAGAKRN_PE20200301_RECLMEXP.TXT\n" "PCMS_Inpatient_Admission_Patients_20190802100552.csv\n" "PCMS_Inpatient_Admission_Patients_20190821154559.csv\n" "Humana Dayton Census - Authorizations 4.30.20 Authorizations.csv\n" "Humana Dayton Census - Authorizations 5.11.20.csv\n" "Humana Dayton Census - Authorizations 4.30.20 Admits Discharges.csv\n" "2020_05_04_Census.txt\n" "2020_05_03_Discharges_Rolling7Days.txt\n" "2020_05_04_Census.txt\n" "2020_05_04_Discharges_Rolling7Days.txt\n" "2019_12_21_Discharges_Rolling7Days.txt\n" "2019_12_21_Census.txt\n" "CHOC_RT_OutreachAttempt_20200502.csv\n" "CHOC_RT_OutreachAttempt_20200509.csv\n" "SGPPN_PE20200101_REMBX.TXT\n" "PriMed_Phy_MAPPO_claim_det_02132020.txt\n" "PriMed_Phy_MAPPO_claim_header_02132020.txt\n" "PriMed_Phy_MAPPO_claim_header_proc_02132020.txt\n" "PriMed_Phy_MAPPO_CLM_DIAG_02132020.txt\n" "PriMed_Phy_MAPPO_member_02132020.txt\n" "PriMed_Phy_MAPPO_member_eligibility_02132020.txt\n" "OHCore_Care_Select_member_eligibility_01232020.txt\n" "OHCore_Care_Select_member_eligibility_04152019.txt\n" "OHCore_Care_Select_claim_det_07152019.txt\n" "OHCore_Care_Select_claim_det_06182018.txt\n" "OHCore_Care_Select_claim_det_01232020.txt\n" "Pioneer_Phy_MAPPO_claim_det_02132020.txt\n" "Pioneer_Phy_MAPPO_claim_header_02132020.txt\n" "Pioneer_Phy_MAPPO_claim_header_proc_02132020.txt\n" "Pioneer_Phy_MAPPO_CLM_DIAG_02132020.txt\n" "Pioneer_Phy_MAPPO_member_02132020.txt\n" "Pioneer_Phy_MAPPO_member_eligibility_02132020.txt\n" "Physicians_Grp_Sohio_MAPPO_claim_det_02132020.txt\n" "Physicians_Grp_Sohio_MAPPO_claim_header_02132020.txt\n" "Physicians_Grp_Sohio_MAPPO_claim_header_proc_02132020.txt\n" "Physicians_Grp_Sohio_MAPPO_CLM_DIAG_02132020.txt\n" "Physicians_Grp_Sohio_MAPPO_member_02132020.txt\n" "Physicians_Grp_Sohio_MAPPO_member_eligibility_02132020.txt\n" "Central_Ohio_PC_MAPPO_claim_det_02132020.txt\n" "Central_Ohio_PC_MAPPO_claim_header_02132020.txt\n" "Central_Ohio_PC_MAPPO_CLM_DIAG_02132020.txt\n" "Central_Ohio_PC_MAPPO_member_02132020.txt\n" "Central_Ohio_PC_MAPPO_member_eligibility_02132020.txt\n" "Central_Ohio_PC_MAPPO_claim_header_proc_02132020.txt\n" "CORECARESELECT1OH_ENC_837P_20190927_529128\n" "Copy of Pioneer_DailyAuth_SummaCare_20191227.csv\n" "Copy of Pioneer_DailyAuth_SummaCare_20200329.csv\n" "Copy of Pioneer_DailyAuth_SummaCare_20200414.csv\n" "Copy of Pioneer_DailyAuth_SummaCare_20200402.csv\n" "Pioneer_DailyAuth_SummaCare_20191227.csv\n" "Pioneer_DailyAuth_SummaCare_20200329.csv\n" "MG 11.22.19 HospitalListReport.csv\n" "Humana COPC Census - Authorizations 3.26.20 Admits Discharges.csv\n" "Humana COPC Census - Authorizations 13.6.20 Admits Discharges.csv\n" "Humana COPC Census - Authorizations 3.26.20 Authorizations.csv\n" "Humana COPC Census - Authorizations 11.01.20 Authorizations.csv\n" "Humana COPC Census - Authorizations 2.2.20 Authorizations.csv\n" "Humana Census - Admits Discharges 20200420.csv\n" "^0420 file bad\n" "Humana Census - Admits Discharges 20200416.csv\n" "Humana Census - Authorizations 20200416.csv") matches = re.finditer(regex, test_str, re.MULTILINE) for matchNum, match in enumerate(matches, start=1): print ("Match {matchNum} was found at {start}-{end}: {match}".format(matchNum = matchNum, start = match.start(), end = match.end(), match = match.group())) for groupNum in range(0, len(match.groups())): groupNum = groupNum + 1 print ("Group {groupNum} found at {start}-{end}: {group}".format(groupNum = groupNum, start = match.start(groupNum), end = match.end(groupNum), group = match.group(groupNum))) # Note: for Python 2.7 compatibility, use ur"" to prefix the regex and u"" to prefix the test string and substitution.

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Python, please visit: https://docs.python.org/3/library/re.html